As my varsity is closed now,i'll take the time to develop a bangla language pack for my favourite site so that it can be fully-banglaized.
I've gone through quite some trouble getting a version of vB at hand,but now i've got a demo one at hand and the language pack will be ready within a very short period.
When done,i'll certainly post it here and sencerely hope BC will adopt that.
For more info,visit this:
http://www.vbulletin.com/forum/showthread.php?t=187384