I wish they would sell the streaming part without the screen. The price is prohibitive and the standalone games seem lame, but I have a nice HDTV in the living room and an ATI GPU that could be replaced.
What, through VNC? That doesn't seem like it would be a very enjoyable experience.
Shield's PC game streaming works by using the hardware H.264 encoder in Nvidia GTX 650 (or higher) graphics cards. They recommend a reasonably fast PC and a fast wireless network.
Does it support an ATI card in the PC?
No, you need an Nvidia card above a GTX 650 because those cards have the built in H.264 encoder necessary to stream the games.