The Google Groups has a number of people who have notified of their project launch. There have been a number of people who have expressed the ease and joy of developing with the PlayFramework.
I myself have built a number of small applications for statistical analysis of one of our internal applications, and I am also in the process of building a much larger site. The simple answer, is that Play just makes life of a coder easier, more rewarding and gives instant feedback (through the real time compilation and in browser errors).
There are a few blogs of people's findings of Play, and you will see plenty of retweets of people who have launched successful applications with Play.
If you are looking for guidance on whether it is the right choice for your business, then it really depends on your business. Play is young, is still growing, but it is a great framework. If you have the opportunity to try it out on a small project, then do so. I very much doubt you will regret it.
EDIT: 2011 Update
I thought I would add a brief update, because a new blog post has been written giving someone's experience and success story using Play, and i thought it would be useful.
http://blog.davejafari.com/experiences-developing-with-play?c=1