A startup called Credder wants to offer a rating system like Rotten Tomatoes, but for news publications. The hope is to offer people a way to check the credibility of a particular website, and rate them.
Startup Credder is trying to solve this problem with reviews from both journalists and regular readers. These reviews are then aggregated into an overall credibility score (or rather, scores, since the journalist and reader ratings are calculated separately). So when you encounter an article from a new publication, you can check their scores on Credder to get a sense of how credible they are.
Sounds like a good idea to me.