I can't think of a cooler improvement to the ASP.NET environment from Microsoft than AJAX. It's finally released and ready for prime-time. Solid documentation, downloads, etc. awaits all who long for a better interactive web experience.
http://ajax.asp.net
ASP.NET AJAX is a free framework for quickly creating a new generation of more efficient, more interactive and highly-personalized Web experiences that work across all the most popular browsers.
With ASP.NET AJAX, you can:
Create next-generation interfaces with reusable AJAX components.
Enhance existing Web pages using powerful AJAX controls with support for all modern browsers.
Continue using Visual Studio 2005 to take your ASP.NET 2.0 sites to...