http://blogs.msdn.com/dawg89/archive/2009/03/19/asp-net-ajax-4-0.aspxGreat MIX09 talk on ASP.NET AJAX 4.0. Stephen Walther is a really great presenter. I’m not an AJAX expert, but the improvements in ver 4 are pretty clear. The big news is vastly improved client-side support. Wrapping your server-side controls with updateen-USCommunityServer 2.1 SP1 (Build: 61025.2)