http://pc.ign.com/articles/965/965535p1.html it's interesting but it believe it won't happen, not yet at least. it could happen sometime in the future but not at the current moment.
I've been checking it out for the last few days and it just sounds too good to be true! I bet there'll be massive subscription costs and there'll be the price of the games themselves. I just see it adding up. Not only that, but you need a good connection if you want good graphics and gameplay. I'm gonna stay sceptical.
I don't really see a use for this service, whichever way you think about it, its still going to be slower than having your own computer up to date, and most pc gamers will prefer to have their system up to date to shave off those few more MSs of latency =/ Could be pretty cool with higher speed wireless cards in laptops though =p