The Web/Live team in Developer & Platform Evangelism has been working on building some new labs, demos, and videos for various web technologies such as the Ajax extensions, RSS, Virtual Earth, and Media Center. This content is available on the Mix University site: http://www.visitmix.com/university
One of the coolest things about this content is that several of the labs use the DinnerNow.net sample application. For example, the RSS lab available here shows you how to build an RSS feed using ASP.NET. This lab consists for five exercises:
Here's a screenshot of the feed after you go through this lab.