I'm curious if its possible to upgrade my Play! 1.2. 4 application to version 2? I know it was a pain to do an upgrade like this with Symfony with their newest version, but maybe its easier with Play!?
No, they changed everything: the routes file format, the template expression language, the whole controller return api (which now is totally asynchronous through Akka). Play2.0 is a totally different product, and I consider it more a Scala stack then a Java one. For example when you create a new app, you are prompted to enter: