I just don't see them coming out with a full featured integrated Nav setup like Google Nav on Android. For the simple reason that they would alienate their App store partners. They make a ton of $ off Nav app's which not only actually sell in decent volume but at way higher $$ then other apps for the most part with some having even recurring cost. People would just want to use the "iMaps" vs buying other 3rd party apps. Look on Android, there's very few Nav offerings and they sell maybe a fraction of the amount Apple App store has b/c Google Nav is just that good.
Guess we'll see, but I doubt Apple will integrate a Nav setup like that, more likely they may do an "updated" version of their maps but not as good/features/voice/integrated as Google Nav.
Who knows though, Apples shown before their cocky enough to go against their App store partners. But with the volume and $ the Nav app's have....., not sure there