its basically DotA
can find in the teamplay section
also, I know that on Higher Ground
(action server) some people like to do some pvp occasionally. the dm-team sometimes hosts a goblins vs kobolds teammatch and theres 1 guild that requires you to beat one of their members in pvp before you are an official member.
actually, I would really like to see more pvp oppertunities on HG. check it out and spam your ideas on the forums. if theyre good ideas and well argued, they might very well be implemented