I think I posted something about these way back in January or whenever...obviously the biggest problem is getting developers to code games so that they can actually use the PPU to render things
But yeah, as far as computers go, I think in the future more components are going to start to branch off with their own dedicated periphials and the actual central processing unit will simply coordinate all these smaller, much more complex processors that all have specific tasks
I would suspect the next thing to come mainstream will be dedicated audio cores
Anyways, the demos they show are really something else though...games will soon be so detailed that you can walk down a street and have blades of grass blowing the wind and god knows what else