Like Steven I've been taking a look at Python or Jython plugins for eclipse. There's a wiki page with links to the various efforts of which it seems this one seems pretty good - though its just a basic editor, no nice code completion or refactoring tools.
There is some discussion on adding a standard Python project to Eclipse - it just seems to need a lead developer to step to the plate. Adding Don's tool into one of the existing eclipse plugins could be a cool start.
I took a closer look at Jason's SureFire, a Jython based unit testing framework he's using which looks pretty cool. Jython unit testing of Java code could really take off - I can already imagine having a JythonUnit plugin for Maven :-)