Thinking of a solution for Yelp's anonymous review system reminds me of how Youtube approached their problem of terrible anonymous video comments by forcing G+ integration.

Everyone bashed/bashes them for the move, but I have noticed a striking contrast in the quality of comments now: largely on-topic discussions, people calling out other posters to substantiate egregious claims etc

I would not mind if Yelp iterated around solutions involving public facing identity.