If you are looking to build your web applications using a MVC approach, I think you'll find this new ASP.NET MVC Framework option very clean and easy to use.  It will enable you to easily maintain separation of concerns in your applications, as well as facilitate clean testing and TDD. 

I'll post more tutorials in the weeks ahead on how the new MVC features work, as well as how you can take advantage of them.

Hope this helps,

Scott