Thing about scene data is that it gets sent once. You then perform transforms on the models, textures & maps etc. I'm figuring that although there will be an initial load phase for complex scenes, textures and the like, there wont actually be an enormous amount of traffic from that point on.
Although graphics rendering is the largest part of a game at the moment, physics and AI are being pushed harder and harder. There are also games out there with huge AI & Physics requirements that are extremely modest in terms of graphics rendering. If I prefer 2D games to 3D shooters, could I not opt for a very basic graphics module?
Sure, this does mean graphics processing and graphics memory at the local end, but this is scaleable no? Android tablets are playing pretty good 3D games at the moment with very little in the way of classic 3D hardware.
This kind of stuff could be included as a modular part of cable set top boxes for example. User then buys the graphics module that suits their needs and the cable company provide low latency connection to their own hosted games servers.