What kind of pc power will you need though? Will there be a requirement ?
you could do it on your cell phone. i was joking, but i think this is what microsoft actually wants.
your "pc" will be basically be just a sliver of microsoft's servers. your actual computer at home will just be the VNC viewer (hence your even cellphone has enough power to view it).
of course, there will be a tiny fraction of a delay, and avid gamers will hate it (like they do onlive), but for the masses it will probably work just fine.
no more updates, no more driver installations (your pc will come as one piece, one board that is part of microsoft's required hardware list so it just connects to the cloud. no upgrading it either, you just pay more money for better cloud service).
i dont like this idea of the future to come, but i think thats exactly what microsoft is going to do- and this is where linux is finally going to gain HUGE ground (linux will be the de-facto for hobbiests and DIY'ers, just like windows was for so many years)