Translatewiki.net is where this work is done and it is for the developers at translatewiki to decide when languages are made available in the MediaWiki interface.
Today in revision 70029, five new localisations were added to MediaWiki, they are:
- Moroccan Spoken Arabic (ary)
- Banjar (bjn)
- Kabardian (kdb)
- Kabardian (Cyrillic) (kbd-cyrl)
- Dutch (informal) (nl-informal)
The rules of the language committee ask for the completion of the "most used" messages but we hope that the messages of the Usability Initiative will also be done because they will have a similar impact.