If you have been trying to sign onto Xbox Live on your Xbox 360 game console and haven't been able to do so today, you have some company. The Xbox Live status page confirms that the online service may be down for some Xbox 360 owners. It may also be down for people who are trying to sign onto Xbox Live from the Xbox.com website.
In addition, Microsoft has also confirmed some issues with signing onto its Zune music and video marketplace as well as Zune.net. Microsoft states that for both services, "We are aware of the problem and are working to resolve the issue. We apologize for any inconvenience this may cause and thank you for your patience." The service outage started earlier this morning, before 12 noon Eastern time.
The same status page also says that the TMZ streaming video page for Xbox 360 owners may also be down for some users. Again, Microsoft says it is working on this issue as well. There's no word on what might be causing the problems.
Update: The Xbox Live status page now says Xbox Live and Zune are back up and running, although the TMZ streaming page is still apparently experiencing an outage.
Source: Xbox Live status page