And OnLive is a great example of marketing gone wild--the technical information their marketing has put out cannot physically all be true at the same time. Some information I've heard, for example:
1. Their system is powered by a JPEG encoder.
2. Their encoder handles one frame per millisecond (1000fps).
3. They plan to do something on the order of 2.5 megabit 720p video.
4. They intend to have extremely low end-to-end latency.
It should be obvious why not all these can be true at the same time. Furthermore, you'll notice other conflicts even if you start ignoring some of the claims: even if 1) is false, 4) basically makes 3) impossible (ultra-low latency has a catastrophic effect on interframe compression).
So at this point I'd pretty much put OnLive in the "extremely dubious" category due to the fact that their marketing can't seen to decide what their technology actually does.