Vista supports a minimum of OpenGL 1.4. If it reports a version lower than that this it's a problem with your graphics card drivers, not with Vista. Older versions of Windows did have OpenGL 1.1 only, but that was always supplanted by the ICDs that video card makers created and included with their drivers. This 1.1 version of OpenGL was software accelerated only, but in Vista the default OpenGL version is actually a wrapper around DX10. It's not as full featured as OpenGL itself, but it should work a lot better for people that don't have a good video card, and it's even hardware accelerated through DX10.
Most people will just be using an ICD though, a full version of OpenGL provided by their video cards. Newer stuff from Intel, AMD/ATI cards, and obviously NVIDIA cards, will be providing an ICD in their drivers so that you can have proper, full OpenGL support.
It's not a great situation overall, but it's considerably better than things used to be. Microsoft may have actually managed to do something a little strange and uncharacteristic here, "a good thing".