CC should have diggable comments, like digg.com, so people are encouraged to make interesting and informative contributions to the site.
There could even be two separate ratings - a “member” rating and a “lurker” rating - since points of view popular among established posters may not be popular among newer users of the site.
Each poster could have a “reputation,” calculated by subtracting his total number of downvotes from his upvotes. Judging members on reputation would be more reliable than judging on join date or post count, currently our only indicators of poster prominence. (Of course posters with a higher post count would have an advantage because they have more posts for people to vote on, but a few very high-quality posts should matter more than many posts of middling quality.)