Since we have plural support for i18n py2.4 is deprecated and does not fully support it except in a default way regarding to bug #3433609. Pre 2.5 releases cannot use plural.py and IMHO we shouldn't downgrade it (look at the code for the reason why). Maybe there is only this guy who is using that old stuff. I guess we should move a copy of the current 2.4 compatible release to the archive without further updates (and maybe make it available at pywikipedia nightly for downloading).
2.6 should be the new minimum version. But we have the unicode bug with all releases from 2.5 upto 2.7.1. This means 2.7.2 is the release which is strongly recommended I think.
Regards xqt