Yelp is obviously very, very good with their SEO. They apparently have the ability to sculpt their internal link values to highlight what appear to be the most popular local businesses in the Google local results.
Apparently their ability to do that in their strongest markets is even greater than elsewhere.
These results, first highlighted by Matt Storms on G+ (h/t to Max Minzer) well before the current local algo update and they are still seen in the SERPS. They reflect on Yelp’s ability to manipulate the search results and reflect poorly on Google’s acceptance of those practices. Yelp, though, needs to be careful of soiling the bed in which they sleep. Although I suppose they could fall back on their all too successful (but BS) cry wolf strategy if Google were to clamp down.