I've been working on my Heroku for Django (or Python more generally) for a month or two now. It's good to see somebody else thinks this is a good idea.
The front end dispatches requests to a Varnish, which is in front of a router that queues up requests and sends them to available copies of the desired application. Persistence is Postgresql, and delayed and scheduled jobs are handled by celery over RabbitMQ.
My number one goal is to provide a deployment environment with as few additional restrictions on the developer as possible.
