Fight! Fight! Shirky vs Rosenfeld in a folksonomy vs controlled vocabulary smackdown. Ha, ha only serious.
One bit left out of the discussion is a minor, but crucial, implementation detail. The vanguard tools, del.icio.us and flickr, let folks watch tags through RSS feeds. Frankly, I think most folks could give a hoot about building an emergent taxonomy. They like being able to easily tag their content and they really like being able to watch how others tag theirs. People are still anxiously awaiting the return of the inbox on del.icio.us.
Forget the whizzy new vocab, I'm all about finding the whizzy new content.