Here some information from the developer-world that might also be of interest to you. AJAX (short for Async Javascript And XML technologies) allows for very nice interactive web-applications (e.g. check out the beta of Windows Live Mail on http://ideas.live.com/), but in my opinion it's quite hard to implement. This is why I find the "Atlas" news from our msdn-colleagues interesting:

The ASP.NET team has just released the March CTP for ASP.NET codename "Atlas," a set of new Web development technologies that integrate client script libraries with the ASP.NET 2.0 server-based development framework. In addition, "Atlas" offers the same type of development platform for client-based Web pages that ASP.NET offers for server-based pages. And because "Atlas" is an extension of ASP.NET, it is fully integrated with server-based services. "Atlas" makes it possible to easily take advantage of AJAX techniques on the Web, and enables you to create ASP.NET pages with a rich, responsive UI and server communication. However, "Atlas" isn't just for ASP.NET. You can take advantage of the rich client framework to easily build client-centric Web applications that integrate with any back-end data provider.

Andreas