For me it's always a quest how to update to a newer TortoiseHg because I need it to work with mercurial keyring extension.
It happens that TortoiseHg doesn't work with mercurial keyring (and related things) installed with normal easy_install or pip, i.e. system ones. For me it only works if I copy mercurial_keyring.py, mercurial_extension_utils.py, and full keyring folder (keyring python module) to TortoiseHg.app/Contents/Resources/lib/python2.7. Note, it doesn't work if I copy egg files for these modules. Another important thing is that version of mercurial keyring and depended modules must match version of TortoiseHg, that is arbitrary version of mercurial keyring won't work with arbitrary TortoiseHg.
Probably others have similar problem, so it would be good to package proper version of mercurial keyring to TortoiseHg installation.