This is excellent! We are on a heroku stack at bizeebee.com now, and if we had to write a facebook app now, there's no question that we'd use this. I had written some apps right after fb platform was released and had to go through hoops to set up my own dev/production environments, manage configurations, deployments, source control etc.

Heroku had taken care of all of that for non-fb apps, and now with tight fb integration, I might just write a few quick fb apps again!

Thanks for the good work, fb and heroku!