Windows Azure Mobile Services are available NOW… here is a quick description of the functionality:

“Windows Azure Mobile Services enables developers to easily add a backend hosted in Windows Azure to their Windows 8 app. With Mobile Services, developers can store structured data, authenticate users, and send push notifications. Subsequent preview releases will expand the feature set as well as add support for iOS, Android, and Windows Phone.”

You can learn more by visiting either the Scott Guthrie’s blog or the Windows Azure blog.  There’s also a ton of fantastic getting started content in the developer center.