Forums by design are very dynamic, the content is static to some extent but it constantly grows. Would it be a fair observation to say established forums have a certain level of immunity to the ups and downs we see in Google? If you think about the forum structure you can have one post grow into many pages of content while at the same time one post may also remain as a stand alone one sentence page that can still rank very well for a given search. My take on this is that above all else fresh content & ovious usser activity rules. I don't know of a single established forum (above 300k posts of real user generated content) that has ever suffered from unexplained googleitis. That is not to say it does not happen but I think it would be rare, I also think there is a lesson to be learned about what Google is looking at when it ranks a site - user satisfaction. I'm not for a second suggesting the results should be full of forums but fresh content will take you a long way these days.
