Yes, that's part of the solution. But it has to be much more robust than "This review was useful". The meta-moderation needs to be recusive, e.g. like PageRank.

The other part of the solution is a review system designed around the fact that people have different tastes. Netflix at least tries to do that. On Yelp, a great hole-in-the-wall will average three stars because those that don't like them will vote the opposite of those that love them. Three stars doesn't help either type of person.