Do you think Apple hasn't been working in this direction since before Steve left the helm?
Placebase acquisition: Jul 2009
Poly 9 acquisition: Jul 2010
C3 acquisition: Aug 2011
I mean obviously if it was a disaster they would have to go back and cut another deal with Google (or Nokia/MS) but it now becomes obvious why they held back turn by turn from the old Maps app for so long. Because you can legitimately argue that 6.0 Maps with some weak spots that can be improved over time but with turn by turn plus possibly Google Maps in the App store is better then 5.0 Maps powered by Google's superior data but without turn by turn.
As far as Google I'd guess they would have been fine to continue powering the default Maps app. Google's price might have gone up from 2007 but the quality increased by a similar amount.