Development is under way
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).
Till next time,
Przemek