Well this is a terrible news for the owners of iPhone 4 and iPhone 3GS, as it has been found that some awesome new features of Apple’s own Maps app for iOS will not be supported by their devices. Apple’s iOS 6 Maps description page clearly states that the turn-by-turn navigation and 3D Maps feature will only be available for the users of iPhone 4S and iPad 2 or later. This is a sad news as these two features are probably the most important ones and are the reason why we all got so excited about the new Maps app.
Some features may not be available in all countries or all areas. Flyover and turn-by-turn navigation will be available only on iPhone 4S and iPad 2 or later. Cellular data charges may apply.
Other than these two features of Maps app, Apple has also kept Siri limited to iPad 3 users, also depriving the iPad 2 users from the personal assistant of their own.