Visit Microsoft KB article 921914 for details. It refers to the prerelease-quality version, but Microsoft has stated that it will work the same way with newer versions as well.

A new version of WGA Notifications has been released and it is now being distributed worldwide.

Microsoft has heard that its customers are disappointed with WGA, and Microsoft is taking steps to resolve the issues customers have had with it.

Oh, you didn't know the previous WGA Notifications tool was beta-quality software? It said so in the EULA when it gets installed, but it was pushed out as a High priority update.