Microsoft is set to roll out some significant changes to its Xbox Live service this year, and wanted to run them by you first. An Xbox Live Update Preview Program is now accepting registrants online, and will grant selected users early access to the Xbox's updated user interface, the Xbox Live on-demand ESPN service, and the enhanced Netflix interface. This is not part of the Kinect beta test, so don't expect a camera to land in your mailbox unless you're also signing up for a reality TV show.
As per Major Nelson's instructions, you can now sign up to Microsoft's Connect website and complete a survey, after which you'll be notified if you've been selected for the program. "Multiple thousands of participants" are sought at this stage, so you might just have a good shot at getting in. You should be aware of some caveats, however: Your ISP must support ESPN 3; you need a Netflix subscription to use the new Netflix search, and an Xbox Live Gold account will afford you "priority" during selection.
The Xbox Live update will introduce a new audio codec for online communication -- if you're selected, your voice chat will become incompatible with the older version. Survey says: "Because you are participating in an exclusive pre-release program, you will not be able to voice chat with non-participants during the preview program period." Game chat should not be impacted, but you've already muted everyone on Halo: Reach anyway.