lets see, it has:
cpu: 700mhz arm11
memory: 256mb (shared video)
gpu: Broadcom VideoCore IV (supports opengl es, 1080p, and h.264/mpeg4 decoder)
video ports: hdmi/composite/dsi
audio ports: hdmi/3.5 jack
usb: 1 port on the a model, 2 on the b model
storage: 1 sd/mmc/sdio slot
network: 10/100 ethernet on the b model only
low level interfaces: 8x gpio, 1 uart, 1 i2c bus, 1 spi bus with 2 select lines, gnd, 3.3v and 5v power buses
power: 500ma/2.5w for the a model and 700ma/3.5w for the b model, power is sourced from microusb or gpio header
size: 85.6mm x 53.98mm
supported operating systems: debian gnu/linux, fedora, arch linux, and risc os
its not a lot but its still pretty powerful for its size. hardware hackers will love the gpio header, which will make it easy to integrate into hardware projects, like using it for quad copters or cnc machine controllers. portable applications seem very possible, its not hard to build a power supply, a couple lithium cells and an lm7805 regulator, battery control chip (for pussies who dont want their batteries exploding) some filter caps and other components. it probably wont be very useful as a desktop, media server client would be a good application, or, with a usb hard drive, a lightweight file server. i guess it would be ok for some older games (probably use it as an open source console if you code it bare metal with a non multitasking game-oriented os). so lots of possibilities here.