Whilst I'm thinking about it.
Why are folders and categories treated separately? Is it for performance reasons when dispatching a request for an item? Is it because folders are the canonical taxonomy when dispatching a request for an item?
Is there a distinction between a taxonomy of categories in which a content item is placed, and a set of keywords assigned to a content item?
I would say that an item is likely to exist at only one point in a category tree whereas it is likely to have many keywords associated with it. I would also say that if categories a more likely to be organised in a tree so that an item automatically exists in the parent categories of it's direct category association - whereas keywords are more likely to be in a flat structure with thesaurus type relations between them. Do these distinctions matter?
