First off, broadband speeds in North Amerca aren't much to write home about. In fact, we're so far behind in broadband technology it's pretty depressing. We're talking a lot of lag here for first person shooter type games. No one wants lag. We can see this being sucessful with slower games like RTS, platformers, etc.
Second, there's the issue of resolution. With the state of North American net connections, we're not going to be able to play games at very high resolutions. We'll be lucky if we can play anything beyond 720p.
Third, most ISPs these days are capping customer bandwidth usage down to miniscule chunks. Don't expect to play for too long with high resolution video constantly streaming to your PC. Instead, expect large connection bills sent to you.
..... AMD Fusion Rendering cloud: win; North American ISPs: fail.