Sources have already said that the iPhone 5 with its elongated screen will come with a home screen that with five rows of icons.
While not proof-positive that the iPhone 5 will come with a higher-resolution elongated screen, it is certainly a strong indication of that. The iPhone 5 won't ship without iOS 6, and vice versa. At the very least, this proves that iOS 6 can scale to the expected 640 x 1,136 resolution.
You can see an image of the expected iPhone 5 screen, here.
possibly a new iPad built specifically to incorporate the new, smaller dock connector that the other new devices will sport.
Other expected changes will be LTE support, a headset jack moved to the bottom of the device, a centered FaceTime camera, and a quad-core processor.