I just asked a fairly detailed question about working with mercurial. Something that wasn’t (obviously) covered on the mercurial wiki, through googling, or in the mercurial handbook, and got a quality answer back in only 8 minutes. That’s fantastic for a general purpose development website and is a great start after only being open for a couple of weeks.
They’ve started up an interesting reward/karma system over there where they award badges (similar to achievements on Xbox360) for a bunch of different positive behaviors. A nice little token system that’s paired with “power-ups” at different point levels. It’s easy to get the first few badges with just a little participation on the website, and I can see how certain personality types that are common in engineers would get big rewards out of collecting these.