The reason for the bad interaction is that some of the tests in test_logging disable all existing loggers (due to the configuration tests - disabling of existing loggers is explicitly tested for), but as a side effect this also disabled the concurrent.futures logger.

I've made a change to test_logging which preserves the disabled state of all existing loggers across tests, and now all is well when testing

regrtest.py test_concurrent_futures test_logging test_concurrent_futures

after applying Brian's patch of 24 Dec 2010.

The change has been checked into py3k (r87513). However, this raises the wider issue of other loggers in stdlib and the effect on them of logging configuration calls. I'll raise this on python-dev for discussion.