Yes, what I find most interesting about listening to the Stack Exchange podcast is how much attention and conscious effort they put into constructing the community, and in a continuous fashion (i.e. it's never finished).

That said, it seems to me that we haven't reached the limits of the machine part of the human-machine moderation team. Voting up and down (here on HN, on Stack Exchange, Slashdot, etc.) is fine, but pretty rudimentary, for example. I'm wondering if there are any others experimenting with more heavily algorithmic moderation.