As noted in my yesterdays blog post about the freeze of Mozmill in the JSBridge module when Python 2.7.2 is used, there was an urgent need for a new version of Mozmill.
Late yesterday we were able to finally release Mozmill 1.5.9 on PYPI. It only includes the fix for bug 722707 and allows everyone who is running on Python 2.7.2 to use Mozmill again. If you are affected please upgrade immediately.