According to trusted sources, Apple has an incredible headline feature in development for iOS 6: a completely in-house maps application. Apple will drop the Google Maps program running on iOS since 2007 in favor for a new Maps app with an Apple backend. The application design is said to be fairly similar to the current Google Maps program on the iPhone, iPad, and iPod touch, but it is described as a much cleaner, faster, and more reliable experience.
Not too surprising, given Apple's penchant for minimizing dependencies on external services, especially Google's. But it's a big move: I'd bet that Maps is one of the most heavily used apps on the iPhone, and I doubt people will tolerate too much in the way of bugginess or lost features. For example, what will happen if you click on a Google Maps-based URL from a friend? Will the new Maps app be able to interpret the link and display the right map? Or will you get punted into Safari to view a Google map in the browser, resulting in a much poorer experience? I hope Apple has thought these things through.
Also, a minor quibble: The maps app on iOS has never been called "Google Maps." People might refer to it that way, but it's always been called simply "Maps."