If an 'other languages forum' means that posts need to be translated into English, I change my vote to no.
Vector is a great distro, and this is a great forum. But you can ask to much of it's members. IMHO what you need as prerequisites for a non-English sub-forum is 1) a healthy group of members who are at least half proficient in the intended language, and 2) someone willing to moderate. And also 3) the sub-forum should add to the forum, not replace any (parts) of it.
That way it'll be easy on the existing participating members, because 1) it's moderated, 2) it's vitality is result of enthusiasm about the existence of the sub-forum; no posts = no enthousiasm ; kill dead forum. And 3) the main parts of the forum remain in English.
Now I already told ya I can sound like a manager
But I'll be quick to give an example, which will be clearer than what I wrote above. I have a Dutch article about \Dutch Governmental 'comply or explain'policy on FOSS (pdf)
in relation to the mandatory Open File Formats in data storage and archiving.
Now if I want to discuss this in relation to a growing local market due to this policy, I can do two things. I can put :(Dutch): before the thread title, or I can put it in the Dutch section. That is neither here nor there though, I wouldn't be posting about that... just couldn't think of another example
To tell you the truth, I don't know if it's feasible to maintain such a forum... Can I change my vote to 'I dont know'?