I would like to have a recipe for deploying from the svn checkout of the dev (or any branch) branch. The idea here is to be able to avoid waiting for the nightly tarball to test fixes.

Here is a brief instruction how to use svn (the net has more complete). This example is aimed at translators but except that part it is the same.
http://www.zenphoto.org/news/translating-tutorial#updating_zenphoto

HOWEVER: I do not recommend deploying from the SVN. There is a subtile distinction. SVN deployments are marked as "developmental" where as Nightly builds are marked as "released" and Zenphoto does behave differently in a developmental environment--it includes debugging code.