A great post by Paul Sandoz on MVCJ. Jersey rocks!
I'm loving the simple JAX-RS POJO based programming model (quite Rails-ish) for writing controllers and models which work beautifully in a hi-RESTful way which also now support a rails-like way of implicit templates via JSP/Velocity/whatever with a minimal amount of fuss.
I'm liking the controller-is-the-model-facade option with implicit MVC too; so the model is totally decoupled from the web and the controller just has a few annotations to deal with binding methods nicely to the URI/REST/content types and so forth - then you can have as many representations of a model as you want - just write views (e.g. index.jsp, detail.jsp, brief.jsp or whatever). Lovely and Rails-ish
Its now pretty easy to write hi-rest web apps in Java which render content as (X)HTML, XML, JSON with nice RESTful content negotiation and using good URIs.