Last month Scott Guthrie had a post about ASP.NET MVC Framework that will be released this year as an optional feature. He intend to post several blog posts that will describe the framework in more detail. His first post is ASP.NET MVC Framework sample application. It's pretty long but very detailed 
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See it here: http://weblogs.asp.net/scottgu/archive/2007/11/13/asp-net-mvc-framework-part-1.aspx