The ASP.NET MVC team is in the final stages of finishing up a new "Preview 4" release. See Scott Guthrie's Blog:  http://weblogs.asp.net/scottgu/archive/tags/MVC/default.aspx .

ASP.NET MVC makes it very easy to implement a model-view-controller (MVC) pattern based Web applications. It also makes the analysis and designing process much simpler for translating Use Cases / User Scenarios through a Boundary / Controller / Entity classes transformation process as detailed in the well respected book "Software Reuse: Architecture, Process and Organization for Business Success", authored by Dr.Ivar Jacobson, et al. This approach definitely helps designers identifying the relevant classes for the UX, Business layers for a Front Controller pattern based implementation. I always felt that it  also helps architects defining application architecture through a process beyond just boxes and lines in describing the architecture.

A few relevant URLs:

Microsoft ASP.NET MVC
http://www.asp.net/mvc/

ARCast - Process Legend Ivar Jacobson
http://channel9.msdn.com/shows/ARCast+with+Ron+Jacobs/ARCast-Process-Legend-Ivar-Jacobson/

"UML Extension for Objectory Process for Software Engineering" -  This document discusses on Analysis Subsystems which include analysis service packages, analysis classes (such as  entity, boundary, and control), and relationships.
http://www.omg.org/docs/ad/97-08-06.doc