Looks like Google is bringing back in-SERP review star ratings and ditching the Zagat rating system it adopted several years ago.
Google appeared to be moving away from the system slightly in 2012, then made another move a few months ago, when it reintroduced a star rating on Google+ pages.
Finally, it looks like the final nail in the coffin for the Zagat rating system as it looks like Google has begun to roll out an update switching everything back to a 5-star rating system. See the screenshots for more:
