Well, in fairness, Heroku is now the Heroku for Python. The new Cedar stack (unofficially) supports Python, and some of the frameworks are already being tested on it (http://docs.pylonsproject.org/projects/pyramid_cookbook/dev/...)

I managed to get into the betas for both ep.io and gondor, but neither has anything near the polish that the Heroku guys have had years to work on.