As I mentioned earlier in the week, tomorrow (Monday, 9/29/2008) from 12:01 AM PST for up to 24 hours, Xbox Live will be offline for maintenance. As a result, Xbox LIVE and the My Xbox section of Xbox.com will be unavailable, and the Xbox forums will be in read only mode (you wont be able to post.) The remainder of Xbox.com will be available with limited interruptions. When the service returns, you will not have any new features and you will not have the new Xbox experience update. That will happen later this Fall. I will update my Twitter when the service returns.
Edit: The LIVE maintenance is taking longer than expected. I’ll have an update at 0200 PT.