Nice point about how this thinking in public is a set of parallel threads that intersect and separate. You get the freedom to reflect on what you're reading in other blogs, but you also get to engage in this loosely coupled interaction.
I wonder if part of what I'm finding valuable in this addition to the broader set of tools for thinking is this degree of “loose coupling?” You're not wrapped up in the middle of an argument, but you also don't have a real opportunity to wander off into the poppies and contemplate your navel. I think this is particularly so if you add in the aggregator/news reader side of this interaction. I'm able to track this evolving exercise in collective reflection without having to go from place to place to follow it. At the same time, all of my reflections are collected in this one spot (and shared via my news feed).