Blogs as conversations

This might seem to be obvious at first, but Don Park's thinking about creating a new category of blogs which surround conversations on a specific topic - and allowing aggregators to pull feeds / info based off that topic. To me, I'd just say use del.icio.us and come up with a mutually agreed upon tag and just go at it - del.icio.us already has the ability to filter or include as you want and has rss already built in. Nuff 'said.