In case you haven’t been watching, Chris Casciano has been pushing in some potential…ful directions lately (“potent” just seems wrong in this context) with microformats. First he releases a script to extract microformats in NetNewsWire then he creates a tool for subscribing to hAtom feeds (which basically allow you to subscribe to an properly marked up HTML document instead of nasty-looking RSS).
On top of that, he pushing the envelope for microformats support in Camino. Not too shabby.
Keep track of this stuff in my Microformats Ma.gnolia group.