The ASP.NET guys at Microsoft released their first ASP.NET 3.5 Extension which includes some cool features like Dynamic Data Support (watch this cool video), Silverlight Support, AJAX Improvements, ASP.NET MVC and more.

I was especially impressed by the dynamic data support which simplifies your data management w/o too much effort. You can read more about the new package features here and to download it here. Try it, its cool.