well.. as trakt.tv seem not to wanna do this in near future, i wrote a greasemonkey/tampermonkey script to at least show localized movie titles...
you can't search with localized title, but movies (not tv shows so war) are simply displayed in your preferd language...
it really would be great to adjust language of the movie and show titles!
site itself would be great as well but not neccessary,
thanks!! (german here)