As an outsider to the entire deal, I think this is pretty exciting. I have good faith in the Spring folks. It will also be much easier to get Groovy and Grails work accepted as viable enterprise solutions now that they're huddling a little under the Spring umbrella. [ November 26, 2008: Message edited by: Marc Peabody ]
I am using grails for prototyping my project. I am liking it very much compared to JSF as it reduces lot of boiler plate code and generates some nice GSP pages CRUD operations. Good support for validation.