Loren Baker gets on the warpath today with this rant against the NoFollow tag. Loren lists 13 reasons why he is against it. He also backed up his rant by installing the DoFollow Plugin, a plugin that causes all comments out of your blog to have the NoFollow tag removed.
NoFollow was supposed to help clean up link spamming in the blogosphere. Well blog spamming is worse than ever. That said, it probably has met the search engine goals in the blogosphere. Blog spamming may be worse than ever for those of us who blog, but the search engines no longer need to worry about the links garnered by blog spamming having an impact on their ranking algorithms.
It's also true that the search engines have expanded the original mission of the NoFollow tag. They want people to use it whenever they sell text links to other sites. In Google's case, at least, if you are found to be selling text links and are not using NoFollow, they may simply discredit your site's ability to pass any link juice.
This latter usage of the tag is a complete bust. People object to the idea and don't want to do it, whether they be buyers, or sellers of links. It's clear that this latter application is a bust.