I've completely rewritten MafiaUpdate from scratch, with a much more modern foundation. The result is MafiaUpdate2.

NOTE: The system requirements for MafiaUpdate2 are significantly higher than the original MafiaUpdate. MafiaUpdate required only Java 6. MafiaUpdate2 is totally rewritten in 64-bit Python, and thus requires a 64-bit OS to run.
Mac users need 10.6.x "Snow Leopard" or later.
Windows users need a 64-bit edition of Windows Vista or 7.
Other platforms need Python 3.2.

The rewrite does bring with it a big advantage over the old one, though - a much simpler update method. Updates to MafiaUpdate2 are delivered silently and automatically applied. The updater even restarts MafiaUpdate2 for you.
The primary download is rather large (14.3 MB), but it is an all-in-one download, meaning the files for all platforms are in there.

To-do list:
Figure out how to make Windows use the same update method as Mac OS X and other platforms do. At the moment, Windows users must download a whole new EXE instead of the much smaller raw python script.
Add back features the older MafiaUpdate has but this newer one does not.
Fixing any bugs that you guys report to me.

MafiaUpdate2 can be found here: http://www.worldwizard.net/kol/MafiaUpdate2/