This reminds me of the prospect of rationalist arbitration that was brought up a while ago. I like the idea of a place where above-averagely rational folks congregate for purposes that aren't related exclusively to the pursuit of ever-greater rationality. However, Less Wrong's only barrier to entry (in the comments, at any rate, which I find comprise about 60% of the site's value) is obscurity and esotericism. Anybody can make an account and post comments (if they suck, they become invisible to people with certain preference settings, but that doesn't prevent further posting). Our high signal to noise ratio comes about because people who spout noise mostly have no interest in us; if we start a sister site where we talk about D&D and kittens and how to get cranberry juice out of upholstery, where's the wall around our garden?