This feature has been added to PyDev 2.0.1 with an option to relaunch the tests in the last test run whenever a python file change, with an additional option to rerun only the errors — although it’ll run the full test suite if no errors were found, as the idea is that you work through your errors and when all pass a final launch for the whole suite is done (then you can move on to another task).
The current nightly build has this feature incorporated.
