The official forum of the publisher CDV. DEAD
A new website opened in 2010 there are some interesting tutorial-videos and various maps(packs) to download. The comunity seems to be nice too.
A spanish BK-site with huge database and a BK2 section as well some nice maps & minimods for download there. I don't speak spanish, so I can not tell anything about the comunity there.
A russian (I think so) fan site. no info, cause I don't understand a word russian!
I'll add others if I find them...