You know what? Maybe they should be discussion boards. If a large number of users seem to use your site's resources in a nonstandard way that a large number of other users find helpful, that might be a hint that you're not in the business you think you're in.
In many areas of business, it also might be a hint that someone is about to disrupt you. If Stack Exchange is the Myspace of Q&A sites, who will be the Facebook?
Jeff Atwood hates "forum style" interfaces and discussions for Q&A sites. I've always disagreed with this. Forum style discussions not only solve problems, but also branch out into brilliant discussions. I myself have been part of a few math forums before.
It could also be showing that an additional product is required, rather than a replacement or dilution of the current one. The world doesn't require the destruction of one product to create another.
Stack Exchange's creator is looking at how to improve forums with Discourse, so that might very well happen.
In many areas of business, it also might be a hint that someone is about to disrupt you. If Stack Exchange is the Myspace of Q&A sites, who will be the Facebook?