The trouble is that folksonomy is used to describe systems that allow users to tag their own content, and systems that allow users to tag the content of others (i.e. delicious).
I’ve told several people that I think author-tagging and reader-tagging are really two different things. I usually just get blank stares when I say this, so I’m glad someone else agrees with me.
Part of the reason reader-created folksonomies is that the terms used to describe the work are in the vocabulary of the reader, not the writer. Authors could never fully imagine how their readers will view their work. For this reason, reader-created folksonomies have a distinct advantage over author-created folksonomies.
I’d be interested to see if there are different patterns in tagging behavior between author-tagging and reader-tagging. I’d suspect that author-tagging tends to be more conservative, using fewer and more established terms, rather than invented or compound terms.