Why would you want to have the admin interface in different languages?
Because I config the forum for an klient and the klient want the admininterface in german. (to my discomfort) The klient is the such pain in the a**! But the klient is the king,.. or however this phrase goes like:P
I don't think that it's a 'time consuming thing to do'. ^^ Maybe a day of replacing some lines and adding some new. The only thing that may be robs some time, is to decide what kind of language system to use. The translations can be made by each individual,... so you don't have to bother w it ;)
The code is not that blown up (my reason to take this forum) & so ya don't have to reedit hundrets of files :P
greets biophonc