It’s a quite typical architecture for Java webapp to have Apache Velocity as templating engine that handles the View part of your MVC.
Well, having worked for a while with it and checking out Groovy now I immediately felt it’s be very interesting to have Groovy there instead of Velocity.
Velocity is sensibly weak in working with arrays and lists. But Groovy on contrary adds more power and convenience in this aspect. And doesn’t seem to be lacking in any other.
It seems someone in 2007 already though about this: http://raykrueger.blogspot.com/2007/07/groovy-views-in-spring-mvc.html
And even more – Grails, the Groovy framework, is actually based on Spring MVC, although this is a bit too much compared to just having Groovy scripts as “views” in Spring MVC.
All in all, it sounds like a good ting to try out.