" I'd be way into this is if it were coming to the UK. right now, I'm not. "If I am not mistaken they have started a limited trial in Europe. There are no promises made with the service, it really depends on if they have a data center close enough to where you live. Try out the PC client and see how it does.
I am really impressed with this technology. I have only ever had issues with the service when running their WiFi beta, but even then the games look great and have minimal lag. Granted my local machine can best this service in any of the games that they have available, so I won't be rushing to buy games from Onlive. I can see a market for this. People just need to give the service a chance.