Xbox Live has a problem, and evidently it's a rather noticeable one. Word on the street has it that a new Modern Warfare 2 map update has made a number of Xbox Live features unusable, including online MW2 gameplay. We're also hearing that the Xbox Live Marketplace is off-and-on, and even Microsoft admits that quite a few other things are acting quirky. The good news is that a fix is on the way, so we'd suggest grabbing that lunch you've been denying yourself and trying again later. Hey, aren't you supposed to be working right now, anyway?
P.S. - Let us know if you're running into any issues in comments below, cool?
Update: Things seem to be working their way back to normal. Phew.
[Thanks to everyone who sent this in]