Sure, there are some serious question marks over things like latency, but come on. It'd be a mean, mean person who wasn't even a little excited by OnLive's potential to change gaming.
Cloud computing, transcending the need for a particular console? Playable on your TV, your PC, or even your Mac? It's ground-breaking stuff. Provided it works.
Speaking of how it works, here are a couple of announcement interview clips, showing exactly that. How it works. Or at least hopes to work.