Here’s an article from the MSDN Magazine, March 2008 issue, about ASP.Net MVC.
Model View Controller (MVC) pattern, as implemented by Microsoft for ASP.Net, is a new web application framework that sits side-by-side with the Web Forms but has a different set of design goals. A few of the main points are that it is extensible and testable. The description from Patterns & Practices site is here.
It will definitely change the way we (developers) interact with the web users and how we create the new generation of applications. It is, finally, a step away from the scripting playground that started with ASP, PHP, and similar languages. Now, the URL as a way of interacting with an application server is more dynamic, configurable, and alive, in a way. Now we have classes (controllers) and different ways to interact with them through URLs (calls). The data (model) is displayed through a web page (view), as usual.
Views now can be Master Pages and regular pages, so page nesting is possible, allowing for a more modular and flexible design. The model can be strongly typed. That way it is accessible to a View through object properties, which implies type checking during compilation time. The view, actually, is a scripted version of the presentation layer and very much more like ASP than ASP.Net.
For the moment, as the technology is still not in its Release stage, Web Forms still have some advantages. But soon after the MVC framework catches up with the UI controls concept it might become more appropriate for a large-scale web development.
To see an introductory video on MVC, click here.