I think most people are missing the point of the new controller.
I think it will have the lobby and friend information on it while you are playing a game on your console.
Similar to the 3DS. You can get messages and chat with your friends while playing a game.
Otherwise everytime your bonehead friend said "wutz up!!" you would get kicked out of Metroid Prime or whatever game you are playing.
I *Think* Nintendo is trying to let players all be connected, even if they are playing different games. The icing on the cake could possibly be "Join now" or "speculate" or send a short movie of a boss fight you just completed or a screenshot.
Now take that and seamlessly tie it into a 3rd party share program like you-tube, and you have a CAFE experience indeed!
New rumor is that the controller contains a front facing camera.
Seems like the obvious use would be for online. Maybe while you're playing a multiplayer game it streams your face to the other person's controller so you can see him while you play? I feel like the angle wouldn't be right, though.