[Update 10:40 am] The Xbox Live Marketplace has been restored according to a tweet from Xbox Support. The status page still shows a service alert for now, but that should be changing soon.
[Original Story] The Xbox Live Marketplace has been experiencing outages this morning, though the problem doesn't seem to extend to other Live features like online play and matchmaking. The Microsoft status notification (via Joystiq) states that users might experience a problem with browsing Indie Games on the Xbox 360 or PC, browsing Games for Windows Live Marketplace on a PC, or browsing the Games Marketplace on a 360 or PC.
"We are aware of the problem and are working to resolve the issue," reads a statement on the site. "We apologize for any inconvenience this may cause and thank you for your patience."
It's hard not to think of the recent Sony hacks, which started with a similar service interruption. But we haven't been given any indication to think a hack has occurred. We've inquired with Microsoft and will update with more information as it becomes available.