Dose has an interesting "first steps" take on knitting the web together into a tighter community-feeling place, through tracking your own comments elsewhere in your own blog sidebar. It's not quite the two way comments infrastructure I and others with me have been dreaming about, but it's nibbling at some of the same ideas.
It's still a very manual, laborious and grassroots kind of business, but it's at least a start, and that is very often enough for things to take off. So dig in, and spread the word. The article user commentary is worth a read, too -- as I reflected myself as well, people suggest tagging comments to limit the scope of your republished comments. Expect something along these lines here too, in a while.