I have read this new MVC Framework. Currently, we are working on DotNetNuke, an Application Framework derived from MS "IBuySpy" Starter kit.

Is this new MVC Framework, a "yet-another-new-framework" ?

Will it support Module development ? like that of DotNetNuke

In what scenario one should move to this Framework ?

I wouldn't compare it to DNN. DNN is a portal platform. This is more of a web application framework. In my first message in this forum, I link to some posts by Scott Guthrie. The first one provides a great introduction to what ASP.NET MVC is.