Interesting discussion about the nature of blogs, blogging, and where this stuff might be going. Some comments jumped out at me:
The whole idea of comments is based on the assumption that most people reading won't have their own platform to respond with. So you need to provide some temporary shanty town for these folks to take up residence for a day or two. And then if you're like Matt--hanging out in dozens of shanty towns--you need some sort of communication mechanism to tie them together. That sucks.
So what's an alternative? Facebook is sort of the alternative right now: company town.
Yeah, I think Dave's ((Winer, with more here)) been consistent for years that commenters should get their own blogs; TrackBack was predicated on the idea that was a viable course of action, so it's certainly not philosophically contrary to what bloggers (used to) want to do.
That being said, I think it's the on-ramp to participation that's broken. Not just signing up, but actually thinking "I'm a blogger" is a big mental hurdle, when in fact anyone who's ever updated their Facebook wall or left a comment is a blogger.
Shanty towns and company towns, rather than walled gardens. Much better descriptions of what these things are now.
Lots more good stuff in the thread. Also of note is that the conversation didn't happen on a blog per se, but in a beta private-conversation-shared-publicly platform. Strange, but interesting...