The next Xbox Live update will deliver Facebook, Twitter and Last.fm, but, Ron Popeil style, wait, there's more!
According to an email from Microsoft, anyway. Get ready for news headlines and dedicated music stores in the Xbox Live dashboard. Since Microsoft expressly said we're not forbidden from discussing this, why not?

U.S. Xbox Live users in the closed preview will see a "News and More" tab in the "Inside Xbox" channel, and it will deliver "a regularly-updated stream of content from MSNBC.com, MSN Autos, The New Yorker and Dilbert,
For rhythm and music gamers, the update will also set up dedicated music stores for Lips, Guitar Hero and Rock Band.

But wait, there's more! "Surprise! - Keep an eye out in the weeks after the preview launches...you never know what might pop up," says the email.
Xbox Live Update Isn't Limited to Just Twitter - Microsoft - Kotaku