Is Yelp Growing Up?

Coming hot on the launch of a new check-in function on it's iPhone app, neighborhood ratings giant Yelp is looking to attract private investment in a plan similar to Facebook and Google's past pre-IPO dutch auction style funding cycle. Given that Yelp's new service fared well in Mashable's latest Face-Off, coming in second to segment leader Foursquare (which has been in the news quite a bit in recent weeks), does this mean that a more Professional Yelp is in the works?