I've just pushed both Mezzanine 3.1 and Cartridge 0.9.3 to PyPI.
This is a huge release! Mezzanine 3.1 is really what 3.0 should have been, which has had quite a rocky road over the last few months - upgrading to Python 3.3, Django 1.6 and Bootstrap 3 all at once brought quite a few bugs along, but these have since been squashed and Mezzanine is very stable.
Along with that, we've a bunch of cool new features too. Here's an overview of what 3.1 brings: