I tried to deploy a Django application with Docker a few weeks ago (using a single image with supervisord), only to discover that, during "docker build", I needed the database already running (so Django could create its database), which was pretty much impossible using a single Docker image and a Dockerfile.

With the new Links functionality, this is much easier, but are you planning to ever have the ability to use a single Dockerfile to deploy an application which may contain multiple images (with links between them)? I want to be able to do "docker build ." and have my application up and running when it finishes.