UPDATE: Xbox Live and Xbox.com are now down. They will be back up sometime within the next 24 hours (on or before 12:00am PST on September 30th).
Xbox Live and sections of Xbox.com will be down starting at 12:01am PST for up to 24 hours.Here is w
hat Major Nelson has to say:
"(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 won’t 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. "
Looks like a good day to get in some single player action.