And if we look at local desktop just as a dumb terminal and using the cloud as the PC , offering compressed display doesn't take that much bandwidth.
And i hadn't seen any really interesting apps in 50/100 mbps networks available around the world.
One example that keeps coming to mind is "real" virtual reality (including next-generation MMORPGs and tele-presence stuff). Consider the bandwidth requirements of a world whose physics are malleable: in-world chemistry, in-world shaping of novel materials, in-world machines that actually work in-world or that function by means of realtime-modifiable embedded scripting, etc. All that state would have to be synchronized across millions of clients in near-realtime, requiring things like vastly distributed P2P "rumor mill" replication protocols.
You can do that with Google Fiber grade Internet access. You can't do that with what we have now.
And the economics will be quite nice for the game developer since they pay per use for onlive servers. Said economics would also be nice (at least in the beginning) , for users who wouldn't need to purchase an expensive machine.
If you have a street full of families with everyone all streaming 1080p near constantly you are going to need to greater capacity.
And that's only at 1080p, what about high resolution 4K displays etc? What about when as well as keyboard and mouse input you want to send output for high precision accelerometers , biometric data etc etc.
What I'm ultimately talking about is a "640k is enough for anyone" mind-lock mentality around bandwidth. There are all kinds of possibilities when you have hundreds of megabits or more to work with.