With the amount of information leaking about the iPhone 5, multiple sources confirm that the new iPhone 5 has a larger screen so will inevitably taller. The shell of the device has been leaked too by many different sources so I think this may be the actual iPhone 5. However no photos have been shown properly comparing the iPhone 5 to the 4S or 3GS.
These shots are the best yet showing how thin the device is. With display technology getting better and thinner and with components inevitably becoming smaller, phones are becoming even thinner. The iPhone 5 is a great example of how thin the device could be. The iPhone 4S is thin itself and still feels thin compared to most devices, but with these side-by-side comparisons the iPhone 5 looks really skinny. It actually makes the 4S and 3GS look fat. It apparently has a thickness of just 7.6mm, compared to the 9.3mm of the 4S.
Of course none of this is confirmed and nothing will be till Apple actually announce the device. But I myself am 70% sure this is what the iPhone 5 will look like.