tlhIngan writes "So why did Apple decide to ditch the (working) iOS maps app with one based on their own data (despite having one more year to the contract)? It turns out to be turn-by-turn voice navigation. It wasn't a feature in the original Apple-Google licensing agreement, so Apple went back to Google to renegotiate what has become a top-tier feature on Android. Apple wanted it. In return, Google wanted increased branding in the maps app (Apple refused) or to integrate Lattitude (Google's FourSquare competitor), to which Apple refused as well. As a result Apple was forced to seek other sources in order to obtain this feature." Link to Original Source
If it happens once, it's a bug. If it happens twice, it's a feature.
If it happens more than twice, it's a design philosophy.