No doubt iPhone 4S user are very pleased that Apple has revealed what iOS 6 will bring in the way of new features; however unfortunately there are some features that will not work or will be neutered on older iOS devices, and this includes the FaceTime app working over a cellular connection.
According to the guys over at Phone Arena, obviously the new Flyover feature wont work on theiPhone 4 as it has a single core processor, and the new Siri navigation will only work on the iPhone 4S and the new iPad because they are the only devices to feature Siri.