I just spent the last 3 hours watching all the latest videos available on the ASP.NET MVC MIX08 Preview Release:
If you haven't done yet, I recommend you to watch them all, especially the last one, which is summing up of all the first 4 screencasts, but enhanced with some technical and architectural details on the framework and the great live speech of Scott Hanselman. On Scott blog you can also find other versions of the video (zune, iPod) and, even if most of the coolness of the session was inside the demos, you can also download the the PowerPoint Presentation as well. And here are the demos. (About the demos, Scott promises will be available shortly).