If you are an ASP.NET AJAX developer, I recommend you grab SP1 of VS2005… Not only does it include tons of bug fixes, but it also includes the first round of basic support for ASP.NET AJAX in Visual Studio… If you are having formatting or incorrect validation (those red underlines) issues using ASP.NET AJAX then you will love SP1.

Go grab it today: Visual Studio 2005 Service Pack 1 (SP1)

There are of course tons of other support as well… check out Omar's post about Visual Studio 2005 SP1 released - details about changes in "web tools" area