Reading through these entries makes me think of aggregators. Not the aggregators we are used to. Those are feeds run by algorithms. I am talking about dumb aggregators - ones where you put in each post by hand (from The Drudge Report to New Futures), where you write to a form and your post appears on the list (like this Blogging Futures thing). Dumb aggregators cannot scale. They exist within small, intimate communities of people.
I mention these because this blogchain makes me think about how we make writing on the web more conversational (I think it was Azlen's post that gave me the thought). Part of that could be a question of how to make each voice more distinct, how to make communities less of a word soup (ie: social media) and more of a chorus of voices.
This is where aggregators come in. I imagine them almost being like a forum, but instead of users acting on behalf of an account on the forum, they are starting threads and topics by linking back to a post on their site. Blogging Futures is like that in a way, but I am imagining it on a bigger scale. What if I could start a topic with a blog post and have others add to the topic from posts on their own site? That way conversation can live across sites but each voice that makes it up can still be read and understood by itself.
Just a thought.