My previous suggestion to move translations to translation platform was ignored, so i have new suggestion:
create mailing list, sourceforge gives such feature, i tested there is only few steps.
why:
all projects has announcements about new versions or updated translation files, smplayer don't has such feature. smplayer has to come to me and announce, now i have go to smplayer forum/svn and see if there is a changes. if there would be mailing list you could announce new version before release and all translators would update their translation, so smplayer would be released fully localized.