The OnLive "Games On Demand" service will launch in the US on June 17th for Mac and PC, and it will cost $15/month. Remind yourself why this is a big deal by revisiting last year's announcement.
Launch titles for the streamed-games service include Assassin’s Creed II, Metro 2033 and Prince of Persia: The Forgotten Sands. Which kind of makes sense, because you really will have to be "always on" connected if you want to play the games. There's a demo of it going on at GDC right now, and tweeters in the audience are saying it looks "amazing". Apparently it needs 1.5mbps. What's the latency like? We just won't know, I suspect, until it goes live.