Major Nelson has made a forum post stating that on May 2nd, there will be some downtime for everything. Many people thought there would be a cool update for E3, but it looks like that’s not really the case, they are just trying to get everything all cleaned and polished for E3.
On Tuesday May 2th from 0200-1500 PT Xbox Live, Xbox.com and the forums will be offline for maintenance.
During this time, Xbox.com, the forums and Xbox Live will not be accessible.
Thanks for your patience