I just noticed a very interesting announcement by Scott Guthrie. Microsoft will officially start co-operating with jQuery development community, adding support for jquery in ASP.NET Ajax, and which also includes Microsoft PSS e.g they take support cases. Read more here.

MS has released ASP.NET 2.0 Ajax templates for VS2008. See: http://blogs.msdn.com/brada/archive/2007/12/19/using-vs2008-to-target-net-framework-2-0-with-asp-net-ajax.aspx