Announced on e3. Coming soon you will be able to link up with Facebook, and twitter through your 360.
360 is looking really good in E3 so far. Especially having taken what are Playstation's probaly two biggest exclusives ; Final Fantasy and Metal Gear Solid. It's a good time to be a 360 owner! :]
not sure yet they just said coming soon over and over again. But I would think it would come as just a plain update same with the radio.