As let us know before, Major Nelson reveals that the newest Xbox Live Upadte is now available the next time you turn on your 360 if its connected to the internet. This mandator update contains features like Facebook, Twitter and Last.fm all popular social networking sites to help you keep up with the world.

• Facebook.2 Update your status to share what movie, game or entertainment you’re enjoying, connect with friends, and view their Facebook stream, status updates and photos on the big screen — all seamlessly integrated and custom-built for Xbox 360. You can even compare your Xbox LIVE and Facebook friends lists to see which of your friends are on Xbox LIVE.

• Zune. Zune video on Xbox LIVE offers a full-fidelity experience with instant-on HD in 1080p and 5.1 channel surround sound. No waiting for downloads or buffering, it’s there at the press of a button. You can also share the experience with up to seven friends through voice chat and Avatar integration on the TV screen — it puts a whole new spin on movie night.

• Twitter.2 Stay in the know by discovering, posting and replying to tweets right on your Xbox 360. You can even view friend profiles, trends and conversations, or search to see who’s tweeting about your favorite game.

• Last.fm. 2 Discover more music and explore endless personalized radio stations with Last.fm on Xbox 360. Skip, “ban” or “love” tracks to create your perfect mix. We’ve even built in “Gamer Stations” with game-related types of music selected specifically for the gaming community. (Available in the U.S. and U.K.).

The update released today so those that manage to get Assassins Creed 2 or Left for Dead 2 will have to update before starting their new purchases.