I'd love to see posts on the rationale between different design decisions, particularly with regards to things that change group dynamics. For instance, putting karma next to someone's name may produce leader-following social behavior, meaning your high-karma users would reinforce general behavior by encouraging other users to behave the same. But that would increase the already prevalent concern of high-karma users overly influencing discussion and getting upvoted based on karma alone. It would be interesting to see all these examples stacked up and then a post about why they went one way or another.