I've been waiting for Yelp to arrive on Android ever since I got my G1 last year. Living in NYC, it is extremely useful. My girlfriend has had it on her iPhone for a long time now, and by default she has hitherto assumed the odious role of "Yelp bitch." Now when we are downtown in the cold looking for some place to eat after a movie, I too can tap away on my phone to find a suitable restaurant. I suspect this may reduce tension in our relationship by 2.3%. Not bad.
Less personally, the arrival of Yelp on Android has me asking a fundamental question about the iPhone's dominance: sure, 100K+ apps is impressive, but as the best of breed continue to appear on Android (Yelp, Pandora & Last FM, Foursquare, Flixster, Twitter (via Twidroid), Facebook), what does volume matter? How much do we value fart applications by the truckload?
I am separating out games as I think this through. The reason being that we are only now seeing Android phones with proper hardware to support this subset of applications. For non-games, though, I think there may be some equalizing afoot.