just some information regarding how Gaikai will be trying to reduce lag for streaming of games over a network.
It's not all about the Internet improving, there is a lot of things that can be improved to reduce Perseverble lag, I think most people have about 100ms lag from the current wireless controllers input and the time it takes your tv to display the input that takes times to render on your console.
So what gaikai will be doing is reducing these times, on the server side they will be looking at reducing the time it takes to render a scene, and a few other things. Next loads of improvements on your client side, time to render from client box to TV wil be reduced, new TVs will have 0ms practically.
And you'll have already noticed that the ds4 is much much faster and has less lag, that's one of the improvements for streaming Sony knew they had to do first. 
All these savings and more add up to reduce the overall lag time. Internet speed isn't about the bandwidth but your hop time and ping to the closest gaikai data centre hub, they will have loads in the future .