I'm excited to see UIs play with gamification. There's not much of this right now and so much potential. Hive (and particularly hive communities) open a lot of options here, which I hope to explore once communities are live. In regards to consensus specifically though, I think megavotes alone would be a big reason to power up. It would allow users to see what their impact could be (I guess, roughly 20X their current max vote).
RE: Feedback Wanted: “Communities” Design Document