I recently talked to a sales rep at PayPerPost about their penalized bloggers, and he tried to assure me that "even though their toolbar (visible) PageRank has been penalized, their links still pass the same amount of PageRank that they ever did." He assured me that many SEO's are still using them effectively by using their "Realrank" scale.
At first, I was thinking, "yeah right." It would make sense for them to say that because they want to sell posts. Of course it would be in their best interest if that where the case.
But then I thought about the fact that the sites who have been penalized for selling links, at least the ones I know of, have not lost their rankings. So if their rankings are still there, possibly PR is as well - even though the toolbar PR is penalized.