I think organized translations only make sense if there are significant amounts of speakers/attendees with a certain language background that do not speak sufficient English. When you organize Wikimania in an English-speaking country, I don't think it would be very efficient to organize translations centrally (on a case by case basis you could ask a volunteer to help out a speaker), in Argentina and Egypt this was of course different (resp. for Spanish and Arab), and in Taiwan it might have helped to have Chinese translators.
So, I guess it could depend on the local situation and what attendees you expect. Edward, how many people do you currently expect from which countries? (rough estimate)?
Lodewijk
Lodewijk