Currently I'm working on an MVC project in which we're considering the use of SubSonic for the DAL, with POCOs sent up to the MVC Controller from the repository.  The default generated classes out of SubSonic use ActiveRecord templating and we really wanted to use the repository pattern...enter version 2.1 of SubSonic and the use of an extra attribute on the XML for SubSonic service providers.  Rob has a pretty good screencast of it over here...and provides a repository template update from his blog so that repository CRUD methods will also accept an IEnumerable<T> allowing you to batch update lists of items.  This is all very cool stuff and is making development life go much faster. Dave is wiring up some MyGeneration templates for some stripped down POCOs and once we get that in place we should have an end-to-end MVC proof of concept up and moving pretty quickly.