I played a couple of hours of some Lego 3D game with game streaming and latency wasn't an issue at all. There are many games out there that don't require twitch reactions.

Many years ago, when the Netflix CEO said that they'd switch to video streaming sometime in the future, I thought it was a crazy idea: how could you possibly have so much bandwidth? (I'm not the worlds greatest visionary.)

I think things may go the same way for streaming. If it's cheap enough with no installation hassle, why not?