A Cre8asiteforums discussion called The Divide Between Search Engines And Seo's - "No Follow" Fiasco points to two somewhat emotional discussions elsewhere on the possible ramifications or practices of using the "rel=nofollow" tag in links.
In one case, the US Federal Trade Commission enters the arena to stir up the pot for paid links.
The thread at Cre8asiteforums points to both discussions and members returned to voice their opinions. Both the Sphinn and SEOFastStart discussions provide a chance to learn more, regardless of who is right or wrong. I was voted completely out into the universe in Sphinn for remarking that PR can't possibly be the "only" reason people submit to blog directories.
Apparently, I'm terribly wrong about that.