Word from Major Nelson’s blog:
Content: Battlefield 3 Beta
Availability: Check availability in your Xbox LIVE region
Dash Text: Join the Battlefield 3 Open Beta! Grab a few friends and jump into the Operation Métro map in Rush mode. Be sure to check out the integrated Battlelog features and share your thoughts on the Open Beta at battlelog.battlefield.com /The BF3 team at DICE
In other words, you can go play the beta now. If you do, let us know what you think.