The concept is very interesting : you just need to rent a server and you don't need to upgrade your computer. Also, I am sure that they will provide a game catalog like Steam does.
However, to my opinion, this system will not work because:
- According to OnLive, you will have to be less than 1000 miles away from a server to play. As a result, they will need a lot of servers to provide *good* pings to costumers. It seems that they consider a ping of 80ms as the limit. So, quality of service will depend a lot on your distance to a server.
- I am sure they have new efficient technologies to compress frames into a video stream but is their method lossless? What final resolution can you get? Full HD? (again, this will surely depends on your distance to a server)
- As an avid player of FPS, I think that a target ping of 80ms is not enough. Even for a RTS with a lot of micro-actions, fighting game or a car race game you will feel it. And I am not speaking about lags. If you don't play those kind of CPU/GPU time consuming games, may be you don't need a high-end hardware...