I think the forum would benefit from kudos/thumbs up system. There is a much more content in the forums than it is in the tutorial section etc. I think people should be able to thank the users that helped them or brought some interesting topics, and the thanks would add up to their reputation (maybe not on 1-to-1 basis, but every 10 thanks would give you a point of rep).
From what I have seen, systems like that encourage helpful community (look at boardgamegeek for example).