Beta is the new passé, and dogfood* is where its at. Calendar and now Web Messenger are now both in dogfoods that are running on external urls (you have to be signed up to the internal dogfoods in order to load the products - ie you need to be a Microsoft employee).
*Dogfood is a term used for internal employee Alpha testing before it goes into beta testing.
Here"s the tiny Web Messenger shot from the homepage (with the new Windows Live Wave 2 UI)