(BTW, I realized now that we need firstly Meta Mediation Committee and only after making such body we should make ArbCom.)
A meta-mediation committee is a good idea. It doesn't need to be done formally, it can just be a page on meta listing people willing to help mediate disputes and what languages they speak. Some mention of their qualifications might also be good. It shouldn't be an elected committee (not worth the hassle), but it might possibly need some restriction on who can join (must be an admin on at least one [not tiny] project, say).