Updating po files does not sound very difficult, I will have a look.
I had a look at po/Makefile. po/lyx.po is generated by a bunch of awk/sed commands (ui_l10n.pot etc). This basically means that the po files can only be updated under *nux, and it is meaningless to port this Makefile to scons, unless I can translate these awk stuff to Python. Cheers, Bo