Outside-in development on Ubuntu

For over 6 months now I've been working on launchpad.net - collaborative development for open source software - using Python (Zope). It's been an unreal experience seeing various testing strategies on such a large code-base, but the two things I miss the most while developing on launchpad are:

1. The ability to do outside-in development properly - as is possible with ruby's Cucumber project (although, this could be used, but it'd be adding yet-another-technology to the stack - I haven't tried pyCucumber, but it doesn't look too active), and
2. Something similar to rspactor - allowing tests to be run automatically as I edit files, and reporting them via the OS's notification system.

But trying to communicate exactly what I mean by that to people who haven't used rspactor or Cucumber is kind-of tricky, so here's a video demo'ing how I'd love to do inside-out development on Ubuntu...