Reader feedback mechanism
I'm a little worried about permanent article rating... but here's a thought...
Most of the benefits of permanent article rating are to flag low quality articles, not to identify high articles. (Just what I'm gathering from looking at Sue's list.) But when it comes to exploits, I'm much more worried about people up-rating a biased article, and then using that as a reason to exclude new contributions (you're lowering the quality). I'm not as worried about people down-rating an article. What's the worst that happens? You force more people to give it their attention.
So instead of a permanent rating system, what we need is a permanent "flag an issue" system? Something that helps us identify areas that need improvement, and cannot be used as a way to hold a bad article in its current form.