Looking forward to what you do! =) (crosses fingers) =)
WUU on linux:
Seems to work just fine - which means it should work just as well on Mac.
Rough instructions for usage on Mac/Linux:
1-mac) Install Python 2.4.4 (direct link to the .dmg)
and wxPython 2.8.
1-linux) Install Python (preferrably 2.4.4) and wxPython ("emerge wxpython" is all you need on gentoo, for instance)
2) Download the latest source from the WUU webpage and extract it to a folder
3) cd into your new folder
4) python WUU.py
5) use WUU :D
6) take a screenshot for me, will ya? (if it works)
(Note that autoupdating and RAR files won't work on other than Windows, but it should handle them gracefully, at least)
EDIT2: Simpler instructions without SVN ;)