All three videos released to-date already have English language transcriptions:
http://commons.wikimedia.org/w/index.php?title=TimedText:Edit_Button.ogv.en.... http://commons.wikimedia.org/w/index.php?title=TimedText:Nice_People_MEDIUM.... http://commons.wikimedia.org/w/index.php?title=TimedText:Wikipedia_User_Name...
Translation is straightforward without the use of any external tools -- just replace "en" with the language of your choice, copy in the English transcription, and start translating.
For transcription, a very open web-based effort, as Michael points out, is http://universalsubtitles.org/ -- dotsub.com is user-friendly and well-established, but deeply proprietary. But at this point, we don't need transcription, just more translation. :-) So please forward this mail to any relevant lists and help us get more TimedText translations. We can then import them into any of the large distribution channels.