When the iPhone 4S was announced, Apple introduced a redesigned 8 megapixels camera system that incorporated a new CMOS sensor, 5 optics instead of 4 with a larger aperture of ƒ/2.4 to be able capture 1080p, as well as to enhance the experience of the iPhone 4S's abilities. Here is an article from 9to5Mac pondering whether the next gen iPhone will top the current generation iPhone:
http://9to5mac.com/2012/09/05/will-the-next-gen-iphone-feature-an-upgraded-camera-system/
http://9to5mac.com/2012/09/05/will-the-next-gen-iphone-feature-an-upgraded-camera-system/