[Sorry, had to split into two posts because of post length limits.]
And OpenGL Extensions Viewer's report for the compatibility profile:
Renderer: ATI Radeon HD 2600 PRO OpenGL Engine
Vendor: ATI Technologies Inc.
Memory: 256 MB
Version: 2.1 ATI-7.4.10
Device: iMac7,1
Shading language version: 1.20
Max texture size: 8192 x 8192
Max texture coordinates: 8
Max vertex texture image units: 16
Max texture image units: 16
Max geometry texture units: 16
Max anisotropic filtering value: 16
Max number of light sources: 8
Max viewport size: 8192 x 8192
Max uniform vertex components: 4096
Max uniform fragment components: 4096
Max geometry uniform components: 4096
Max varying floats: 128
Max samples: 8
Max draw buffers: 8
Extensions: 131
GL_APPLE_aux_depth_stencil
GL_APPLE_client_storage
GL_APPLE_element_array
GL_APPLE_fence
GL_APPLE_float_pixels
GL_APPLE_flush_buffer_range
GL_APPLE_flush_render
GL_APPLE_object_purgeable
GL_APPLE_packed_pixels
GL_APPLE_pixel_buffer
GL_APPLE_rgb_422
GL_APPLE_row_bytes
GL_APPLE_specular_vector
GL_APPLE_texture_range
GL_APPLE_transform_hint
GL_APPLE_vertex_array_object
GL_APPLE_vertex_array_range
GL_APPLE_vertex_point_size
GL_APPLE_vertex_program_evaluators
GL_APPLE_ycbcr_422
GL_ARB_color_buffer_float
GL_ARB_depth_buffer_float
GL_ARB_depth_clamp
GL_ARB_depth_texture
GL_ARB_draw_buffers
GL_ARB_draw_elements_base_vertex
GL_ARB_draw_instanced
GL_ARB_fragment_program
GL_ARB_fragment_program_shadow
GL_ARB_fragment_shader
GL_ARB_framebuffer_object
GL_ARB_framebuffer_sRGB
GL_ARB_half_float_pixel
GL_ARB_half_float_vertex
GL_ARB_imaging
GL_ARB_instanced_arrays
GL_ARB_multisample
GL_ARB_multitexture
GL_ARB_occlusion_query
GL_ARB_pixel_buffer_object
GL_ARB_point_parameters
GL_ARB_point_sprite
GL_ARB_seamless_cube_map
GL_ARB_shader_objects
GL_ARB_shader_texture_lod
GL_ARB_shading_language_100
GL_ARB_shadow
GL_ARB_shadow_ambient
GL_ARB_sync
GL_ARB_texture_border_clamp
GL_ARB_texture_compression
GL_ARB_texture_compression_rgtc
GL_ARB_texture_cube_map
GL_ARB_texture_env_add
GL_ARB_texture_env_combine
GL_ARB_texture_env_crossbar
GL_ARB_texture_env_dot3
GL_ARB_texture_float
GL_ARB_texture_mirrored_repeat
GL_ARB_texture_non_power_of_two
GL_ARB_texture_rectangle
GL_ARB_texture_rg
GL_ARB_transpose_matrix
GL_ARB_vertex_blend
GL_ARB_vertex_buffer_object
GL_ARB_vertex_program
GL_ARB_vertex_shader
GL_ARB_window_pos
GL_ATI_blend_equation_separate
GL_ATI_blend_weighted_minmax
GL_ATI_separate_stencil
GL_ATI_texture_compression_3dc
GL_ATI_texture_env_combine3
GL_ATI_texture_float
GL_ATI_texture_mirror_once
GL_EXT_abgr
GL_EXT_bgra
GL_EXT_bindable_uniform
GL_EXT_blend_color
GL_EXT_blend_equation_separate
GL_EXT_blend_func_separate
GL_EXT_blend_minmax
GL_EXT_blend_subtract
GL_EXT_clip_volume_hint
GL_EXT_compiled_vertex_array
GL_EXT_draw_buffers2
GL_EXT_draw_range_elements
GL_EXT_fog_coord
GL_EXT_framebuffer_blit
GL_EXT_framebuffer_multisample
GL_EXT_framebuffer_object
GL_EXT_framebuffer_sRGB
GL_EXT_geometry_shader4
GL_EXT_gpu_program_parameters
GL_EXT_gpu_shader4
GL_EXT_multi_draw_arrays
GL_EXT_packed_depth_stencil
GL_EXT_packed_float
GL_EXT_provoking_vertex
GL_EXT_rescale_normal
GL_EXT_secondary_color
GL_EXT_separate_specular_color
GL_EXT_shadow_funcs
GL_EXT_stencil_two_side
GL_EXT_stencil_wrap
GL_EXT_texture_array
GL_EXT_texture_compression_dxt1
GL_EXT_texture_compression_s3tc
GL_EXT_texture_env_add
GL_EXT_texture_filter_anisotropic
GL_EXT_texture_integer
GL_EXT_texture_lod_bias
GL_EXT_texture_mirror_clamp
GL_EXT_texture_rectangle
GL_EXT_texture_shared_exponent
GL_EXT_texture_sRGB
GL_EXT_texture_sRGB_decode
GL_EXT_timer_query
GL_EXT_transform_feedback
GL_EXT_vertex_array_bgra
GL_IBM_rasterpos_clip
GL_NV_blend_square
GL_NV_conditional_render
GL_NV_depth_clamp
GL_NV_fog_distance
GL_NV_light_max_exponent
GL_NV_texgen_reflection
GL_SGI_color_matrix
GL_SGIS_generate_mipmap
GL_SGIS_texture_edge_clamp
GL_SGIS_texture_lod
Core features
v1.1 (100 % - 7/7)
v1.2 (100 % - 8/8)
v1.3 (100 % - 9/9)
v1.4 (100 % - 15/15)
v1.5 (100 % - 3/3)
v2.0 (100 % - 10/10)
v2.1 (100 % - 3/3)
v3.0 (95 % - 22/23)
v3.1 (25 % - 2/8)
v3.2 (70 % - 7/10)
v3.3 (10 % - 1/10)
v4.0 (0 % - 0/14)
v4.1 (0 % - 0/7)
v4.2 (0 % - 0/12)
OpenGL driver version check (Current: 2.1 ATI-7.4.10, Latest known: 2.1 ATI-7.4.10):
Latest version of display drivers found
According the database, you are running the latest display drivers for your video card.
Compiled vertex array support
This feature improves OpenGL performance by using video memory to cache transformed vertices.
Multitexture support
This feature accelerates complex rendering such as lightmaps or environment mapping.
Secondary color support
This feature provides an alternate method of coloring specular highlights on polygons.
S3TC compression support
This feature improves texture mapping performance in some applications by using lossy compression.
Vertex array range support
This feature improves performance in some applications by using AGP for dynamic vertex transformation.
Texture edge clamp support
This feature improves texturing quality by adding clamping control to edge texel filtering.
Vertex program support
This feature enables a wide variety of effects via flexible vertex programming (equivalent to DX8 Vertex Shader.)
Fragment program support
This feature enables a wide variety of effects via per pixel programming (equivalent to DX9 Pixel Shader.)
Texture anisotropic filtering support
This feature improves the quality of texture mapping on oblique surfaces.
Occlusion test support
This feature provides hardware accelerated culling for objects.
Point sprite support
This feature improves performance in some particle systems.
OpenGL Shading Language support
This feature enables high level shading language for shaders.
Frame buffer object support
This feature enables render to texture functionality.
Extension verification:
GL_ARB_depth_buffer_float has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_depth_clamp has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_draw_elements_base_vertex has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_draw_instanced has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_framebuffer_object has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_framebuffer_sRGB has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_instanced_arrays has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_seamless_cube_map has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_ARB_sync has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_EXT_packed_float has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_EXT_texture_array has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_EXT_texture_shared_exponent has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_EXT_timer_query has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_NV_conditional_render has been added to the extensions list of ATI Radeon HD 2600 PRO OpenGL Engine
GL_AMD_conservative_depth was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMD_debug_output was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMD_depth_clamp_separate was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_AMD_draw_buffers_blend was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_AMD_name_gen_delete was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMD_performance_monitor was not found, but is available in driver version 2.1.7415 Release
GL_AMD_sample_positions was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMD_shader_stencil_export was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMD_vertex_shader_tessellator was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMDX_debug_output was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_AMDX_name_gen_delete was not found, but is available in driver version 3.2.9704 Forward-Compatible Co
GL_AMDX_vertex_shader_tessellator was not found, but is available in driver version 2.1.7659 Release
GL_APPLE_container_object_shareable was not found, but is available in driver version 3.2 ATI-7.4.10
GL_ARB_blend_func_extended was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_compatibility was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_copy_buffer was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_ARB_draw_buffers_blend was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_ES2_compatibility was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_explicit_attrib_location was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_fragment_coord_conventions was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_geometry_shader4 was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_get_program_binary was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_map_buffer_range was not found, but is available in driver version 2.1.8664
GL_ARB_occlusion_query2 was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_occlusion_query2 was not found, but is available in driver version 3.2 ATI-7.4.10
GL_ARB_provoking_vertex was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_sampler_objects was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_separate_shader_objects was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_shader_bit_encoding was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_shader_precision was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_shader_stencil_export was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_texture_buffer_object was not found, but is available in driver version 2.1.8664
GL_ARB_texture_buffer_object_rgb32 was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ARB_texture_multisample was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_texture_rgb10_a2ui was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_texture_snorm was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_ARB_timer_query was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_timer_query was not found, but is available in driver version 3.2 ATI-7.4.10
GL_ARB_transform_feedback2 was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_transform_feedback3 was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_uniform_buffer_object was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_vertex_array_bgra was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_vertex_array_object was not found, but is available in driver version 2.1.8664
GL_ARB_vertex_type_2_10_10_10_rev was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_ARB_viewport_array was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_ATI_draw_buffers was not found, but is available in driver version 2.0.6645 Release
GL_ATI_envmap_bumpmap was not found, but is available in driver version 2.0.6645 Release
GL_ATI_fragment_shader was not found, but is available in driver version 2.0.6645 Release
GL_ATI_meminfo was not found, but is available in driver version 2.0.6645 Release
GL_EXT_copy_buffer was not found, but is available in driver version 2.1.8664
GL_EXT_copy_texture was not found, but is available in driver version 2.0.6645 Release
GL_EXT_depth_buffer_float was not found, but is available in driver version 6.14.10.8086
GL_EXT_direct_state_access was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_EXT_draw_instanced was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_EXT_histogram was not found, but is available in driver version 3.2.9704 Forward-Compatible Co
GL_EXT_packed_pixels was not found, but is available in driver version 2.0.6645 Release
GL_EXT_pixel_buffer_object was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_EXT_point_parameters was not found, but is available in driver version 2.0.6645 Release
GL_EXT_subtexture was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texgen_reflection was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture3D was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_buffer_object was not found, but is available in driver version 2.1.8664
GL_EXT_texture_buffer_object_rgb32 was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_EXT_texture_compression_latc was not found, but is available in driver version 2.1.8664
GL_EXT_texture_compression_rgtc was not found, but is available in driver version 2.1.8664
GL_EXT_texture_cube_map was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_edge_clamp was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_env_combine was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_env_dot3 was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_lod was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_EXT_texture_object was not found, but is available in driver version 2.0.6645 Release
GL_EXT_texture_snorm was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_EXT_texture_swizzle was not found, but is available in driver version 2.1.8664
GL_EXT_vertex_array was not found, but is available in driver version 2.0.6645 Release
GL_IBM_texture_mirrored_repeat was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_KTX_buffer_region was not found, but is available in driver version 2.0.6645 Release
GL_NV_copy_depth_to_color was not found, but is available in driver version 2.1.8664
GL_NV_explicit_multisample was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_NV_float_buffer was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_NV_half_float was not found, but is available in driver version 3.2.10151 Core Profile Forward
GL_NV_primitive_restart was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_NV_texture_barrier was not found, but is available in driver version 3.3.10362 Compatibility Profil
GL_SUN_multi_draw_arrays was not found, but is available in driver version 3.0.8787 Forward-Compatible Co
GL_WIN_swap_hint was not found, but is available in driver version 2.0.6645 Release
WGL_AMDX_gpu_association was not found, but is available in driver version 2.1.8664
WGL_ARB_buffer_region was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_create_context was not found, but is available in driver version 2.1.8664
WGL_ARB_extensions_string was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_make_current_read was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_multisample was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_pbuffer was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_pixel_format was not found, but is available in driver version 2.1.7659 Release
WGL_ARB_pixel_format_float was not found, but is available in driver version 2.1.8664
WGL_ARB_render_texture was not found, but is available in driver version 2.1.7659 Release
WGL_ATI_pixel_format_float was not found, but is available in driver version 2.1.7659 Release
WGL_ATI_render_texture_rectangle was not found, but is available in driver version 2.1.7659 Release
WGL_EXT_extensions_string was not found, but is available in driver version 2.1.7659 Release
WGL_EXT_framebuffer_sRGB was not found, but is available in driver version 2.1.7659 Release
WGL_EXT_pixel_format_packed_float was not found, but is available in driver version 2.1.7659 Release
WGL_EXT_swap_control was not found, but is available in driver version 2.1.7659 Release
WGL_I3D_genlock was not found, but is available in driver version 2.1.8664
WGL_NV_swap_group was not found, but is available in driver version 2.1.8664
Note that this post isn't to report any particular issue. I was just wondering how much benefit OS X users were getting from Lion OpenGL-wise.
Thanks.