I don't think I'll find much resistance for saying that Google Maps offers the best map interface for any device you happen to be using. Well, if that device is an iPhone, with the next release of iOS you may found yourself using a map app by Apple, not Google. Can Apple offer something better?
If you're just hearing about this for the first time, it may come off as Apple being petty, ditching a competitor's platform for a lesser option. What's going on here is that Apple has actually been ramping up for this move for a while, and it's seen as inevitable.
There's this from PCWorld's Jared Newman:
Apple's desire to oust Google Maps from the iPhone is no secret. Apple has acquired several mapping companies over the years, including C3, Placebase and Poly9, and the iOS version of iPhoto uses Open Street Maps instead of Google Maps outside the United States.
C3, which Apple snatched up last year, has some pretty impressive 3D modeling chops.