I think higher internet speeds can offer game developers to start putting pressure on ISPs to actually improve infrastructure. If there's a market for it?, they'll build it -- if anyone can put pressure on Comcast or TW, it's Sony and Microsoft. Given enough bandwidth or electrons or whatever makes the internet work, you open the door to realistic multi-party combat, even with present tech like the kinect, and all sorts of other cool concepts I can't even spend the time to think of right now.
Remember how "online gaming" used to be playing chess on the university network? And now you can go kill dragons with people from other continents in real time and get paid real cash monies for it? Imagine what comes next!