My Xbox and the all new Xbox.com forums are online -- Posted by XanTium on October 28 12:44
From majornelson.com:
A few moments ago, we brought another piece of the Xbox.com and Xbox Live up upgrade online. "My Xbox" and the Xbox forums are now available for everyone to check out and enjoy. Do you have an Xbox Live Gamertag already? You can now go in and start setting up your profile in preparation for your Xbox 360. We also have an enhanced My Friends' section, along with My Achievements' (which won't be very exciting until people start playing Xbox 360 games!) Also, when you go to post in the Xbox forums...your gamercard will be right there next to your Gamertag (which is also your forum name.)
Click here to set up your profile (if you are already gamertag linked.)
P.S. If you don't have a gamertag, you can sign up for one and reserve it for your Xbox 360 experience.