This seems like a neat problem. Would it be hard to go from a python function that takes a set of comment upvote downvote counts and returns a ranking to a comment sorting option? If I don't know much about the reddit internals?
Also, would it be difficult to get a real dataset of comment counts from LW?
Way back in October 2009 Reddit introduced their "Best" comment sorting system. We've just pulled those changes into Less Wrong. The changes affect only comments, not stories.
It's good. It should significantly improve the visibility of good comments posted later in the life of an article. You (yes you) should adopt it. It's the default for new users.
See http://blog.reddit.com/2009/10/reddits-new-comment-sorting-system.html for the details.