It's official, ASP.NET AJAX (formerly known as ATLAS) has just been released. Everybody is speaking about it: ScottGu, Nikhil Kothari.
Here are the official download link, the link to the docs (with video tutorials, too), and, for readers that still don't know what ASP.NET AJAX is, there is also an "About" page.
Also, the ASP.NET Podcast by Wally produced a lot of nice shows about ASP.NET Ajax and its Control Toolkit, both audio only and video.
A funny thing is that the main blog about AJAX, ajaxan, doesn't say a word about it.
UPDATE: A few hours later this post, also ajaxan wrote a post about the release.