Major Nelson has announced in his blog, that Xbox Live is due for a brief maintenance downtime today at 11.0014.00 CET. The maintenance also affects Xbox.com´s ”My Xbox” section and the forums. My Xbox is unavailable and the forums are in ”read only” mode. Otherwise the site is available for your browsing pleasure.
He also emphasizes that this is only server maintenance no new features will be added. If you want to find out what time the maintenance is on your time zone click this link.
So, if you aren´t at work, maybe it´s time to brush up those single player skills. Or, God forbid, go outside.