^Well that's rather friggin cool.
But my idea is to take an xbox, and make it run through a PC, as in the audio-visual output not being a screen per se, but an augmented screen inside the computer, which then can be sent through the graphics card up unto the actual screen.
You don't stress the computer with anything more than a simple screen emulator, as anything technical is handled by the console.
Could also be possible to make a split harddisk so the PC and the xbox shares the same memory unit, but then again, I don't know how the xbox' memory system works. Should be possible, but hey, it's theory.