When you look at all this taxonomy-related talk, you may notice a major question - how to assign terms to content?
It was mentioned, that it is going to be done, with and without a hack, but in fact, the more I think about it, the more I see a need for a CCK component, that would go beyond tagging. But what is CCK?
Content Construction Kit is a module of Drupal that extends it in a remarkable way: you can create your own types of content and define structure of those types - make your own fields.
The development of the taxonomy component is well under way. The basic skeleton is done, data model and the first API (mostly towards plugins). There is a Term Manager and Taxonomy Manager working, and while it doesn't offer any hierarchical visualization of taxonomies, it is quite useful right now.
Have a look (it has out-dated Joomla looks, but well, it's designed for J!1 right now).
Joomla needs a taxonomy extension. I've started working on such a taxonomy component for Joomla, allowing complex hierarchies of content and multiple categories.
When I first set my foot on the land of Joomla! over a year ago, I pretty quickly started to like the flexibility and hackability of Joomla!, until the moment I needed to migrate it to a more recent version... But this is not the subject here. I have also discovered a major flaw - very rigid and simplistic taxonomy. The sites I've been working on at that time started then to discover that this single section - category approach is pretty limiting. When I have created my custom solution towards multi-site Joomla installation, my major problem started to be exactly this - how to create separate taxonomies for separate sites?