I've talked to a few people about this over the past few weeks, I am tremendously excited about where this will be going. Scott Hanselman has posted a link to some presentations on this. Over the past few years I've written 5-6 of this type of framework (MVC / MVP based, URL redirection etc...nowhere near as complete or elegant of course!) and ASP.NET adding this type of functionality is a massive move forward. Of course this is only the beginning!