There were a lot of great sessions at MIX this year and in case you missed them, I wanted to let you know where you can find them at. For individual sessions, you can go here.
But there is a better way to go through some of the really cool information that was there. On the website for MIX, they have created a University. This is a great place to learn about many of the new technologies. From Silverlight to AJAX to Media Center. There are some great details here including multiple demos and a Hands on Lab for most of of the areas.
Then if you look on the right side of the university page, you will see a link to some case studies. This is a great way to see how some other companies are using some of these new technologies.
By far, the coolest sample or demo on there is the DinnerNow site. This site is a sample that demonstrates so many of the different technologies that is it hard to list them all. According to the site: IIS7, ASP.NET Ajax Extensions, LINQ, Windows Communication Foundation, Windows Workflow Foundation, Windows Presentation Foundation, Windows PowerShell, and the .NET Compact Framework.
I would highly suggest that you try this sample and download the project. It can give you many insights into how all these technologies can come together to make something really great.