Assuming paid/exchanged links are the cause, it's odd that the directories were hit in the SERPs but not the blogs, or at least not yet. So it could just be a matter of time for the blogs to be similarly hit or there may be a specific causation to the directory penalty.
I have a suspicion that most of these larger blogs were hand editted. Most likely just a tactic to scare us all off buying/selling links.
Right, but the penalty the directories suffered was substantially more severe IMO, and they now seem to have also incurred the PR drop, so a double whammy...