I tend to think this is a moot question and that panda is not targeted at a specific type of site.
If you have a forum, and it is full of crappy, thin articles with weak responses, then I hope the Panda bitch slapped you down the rankings.
On the other hand, if your forum is absolute dripping with awesome and the community is alive and kicking then it deserves to rank well.
All this classification is wrong and the content farms did not get punished because they are content farms, they got punished because they allowed people to post barely literate heavily spun articles as they greedily wanted the adwords revenue.
If Forest Gump was online he would say something like, Content is as Content does, and I think that just about covers it. :)