I'd be keen to have a feature in which I could more easily ignore posts from the nut jobs and see the posts from the brighter members of the forum. One method would be to have a feature permitting users to annotate user names, visible only to the user who made the annotation. It would be even better if threads didn't move up to the top for me just because one of the nuts posted. One could imagine several methods of implementing such a feature. Even just setting up the forum such that you get updates when chosen members post would be grand.

Also I'm rather opposed to like/up vote/down vote systems.