I have to jump in with everyone else. Me too, me too! :D
http://ajax.asp.net/
In the coming months you will see our platform pushed to Channel 9 and 10 and we use ASP.NET AJAX heavily. Hopefully I'll have time to work up some samples from our code to share.
http://on10.net/tags/CES
Keep checking back for more. We've got a lot of great stuff lined up! :)