Facebook seems be quietly adding threaded comments, voting, and other interactive features to the commenting platform. You can see it in action here, on the Facebook blog, and see what you think. The voting seems like it could work as a kind of a "don't-like" to counter the "like" feature, though it doesn't seem as though voting will change the order in which comments appear, as it does on other sites. The votong does seem like it has the potential to make people a little combative, no?
Also noteworthy is the fact thatcomments will now display a user’s location or company or school, depending on your profile, which I hope is something you can turn off.