Microsoft announced today information about an initiative for supporting Asynchronous JavaScript (AJAX) in ASP.NET 2.0. AJAX is not a new technology but has been used recently by such companies as Google in Google Maps and GMail. AJAX allows client-side script to make calls to the web server without issuing a postback and therefore making the user experience much smoother and more enjoyable.
Scott Guthrie is the person inside of Microsoft who is responsible for incorporating such technologies. You can read more on his weblog for more information.