I am a fan of this, definitely -- I think an important role for shepherds (or maybe others too) ought to be summarizing. That is, in my ideal world, we'd start a thread with some amount of focus, discuss things, and then produce a link to the thread along with a link to an (in-thread) summary of what led up to it. It doesn't have to address every post: but it should be enough that people don't have to read all the prior posts to feel caught up.
Part of the reason to do the summary in-thread is to allow people to respond (in-thread) to clarify or add missing bits to the summary.