I've just started using Dotcloud for some Django projects, and I just want to say I absolutely LOVE how easy it is to set up apps, databases, etc, despite the beta state and the limited documentation at the moment. Highly recommended.
It's because of Dotcloud that I'm not currently in the pits of despair and can concentrate on my application and my users...and commenting on HN.
I can't recommend them enough.
Also happy to give out invites to fellow HNers!
I've had experience with a number of the 'heroku for Django' startups going around, and while I don't have any complaints against any of them, dotcloud is KILLING in this space.
The best part, to me, is not having to mess about with various components -- I was able to put together a wordpress/mysql stack for one project, Django/Postgres for another, and Flask/mysql for another with the same interface, the same ease of use, and the same instant gratification.
It really is gold.
I don't have to worry about forcing myself to use RoR because there was only Heroku anymore.