Hi. We use Play! Framework in production since a year ago.

We have two sites, http://www.masterbranch.com which is a site to manage developer CVs and track your open source experience in your CV. The other one is a network about developers, sysadmins, web designers (this one is in spanish) http://es.debugmodeon.com

We are happy with Play!. It's easy to use, has lots of built-in features and Play! team is also awesome and their work is exquisite.

Cheers