Many of you have probably heard that we’ve released ASP.NET Ajax Preview 5 on Codeplex, and it’s available here.  Aside from all the cool updates to the codebase, Preview 5 also includes some updated samples, as well as support for UpdatePanel when using ASP.NET 3.5 SP1. 

Previously, this didn’t work because of updates to the scripts for compatibility with 4.0.&