Our general strategy is to rely on the community for most of the moderation. Right now, users have simple, equal voting privileges on every question/answer. In the future, we're going to incorporate per-channel reputation that is accumulated through the bounty earning process. So each user would start with 1 reputation, and as they answer questions and have their answer voted on by others, they accumulate reputation. This reputation in turn translates into greater voting power on other answers within the channel. Certainly not a silver bullet, but that's where we'll start.