There is a new Atlas RC available for download. 
This one has got really cool new features.  If you haven’t looked at atlas before you should look at it now.

AJAX just became as simple as 1-2-3.

Nikhil Kothari blogs about the new features :

A quick tour of Atlas December CTP :
http://www.nikhilk.net/AtlasM1.aspx

The role and functionality of the Atlas Scriptmanager :
http://www.nikhilk.net/AtlasScriptManager.aspx

That should get your appetite for AJAX going :-D