I saw a post by Tantek Celik today describing how he created an h-feed microformat from a list of HTML elements. He then showed how this microformat could be read and parsed by the Monocle feed reader. He then pointed to a post by James Gallagher about how he publishes h-feed and uses the Granary tool to convert to RSS and other feed formats.
This is an interesting topic. I have looked at microformats before, to me it seems to be a way of adding to HTML to make it machine-readable without the construction of a separate feed. I have nothing against innovation in feeds, but I am not sure how popular the use of microformats is within the feed reader ecosystem.