Phil Haack, one of key guys behind ASP.NET MVC provides an insight on new in Preview 4 for Channel9. He shows where they are going and what you can expect in future releases.
This is a pretty nice implementation on top of ASP.NET. There is still a lot of feedback that ASP.NET makes it too complex. Thoughts?
You can get the bits here
MVC Preview 4 with Phil Haack