... well, up to version 1.0 anyway. Scott Guthrie has all the details on his blog.

ASP.NET AJAX version 1.0 (the project formerly known as Atlas) is basically a framework for building AJAX functionality into .NET app's and it won't give you much out of the box. That's where the ASP.NET AJAX Control Toolkit comes in. 30 AJAX enabled controls for your UI pleasure - check the control demos on the web page. Best of all the control toolkit is is a community based development effort and is therefore released under an open-source style licensing model so you can see how the controls work, hack away at them and release your own varieties if you're that way inclined.

Being an official 1.0 release also means that it gets the full MS support life cycle behind it and that it works properly with .NET 2.0 & VS2005. It'll be interesting to see how many other controls start popping up now that Atlas has finally made it to a final release.