KPlayer is approaching 0.5 release, it should be out in about three weeks.
Italian and Catalonian translations each have about 117 messages to translate, and contact has been lost with the respective translators. So if you want KPlayer translation for your language to be complete, please look at the instructions at http://sourceforge.net/docman/display_doc.php?docid=22175&group_id=71710
Other existing translations are Czech, Danish, Finnish, French, German, Russian, Simplified Chinese and Spanish. If you would like to help with any of these, please contact the respective translators.
If you would like to add a new translation, please follow the link above to the KPlayer Translation Micro-HOWTO.