Periodically, Apple makes quantum shifts in product design. Remember when they switched from the "iLamp" iMac (G4) to the now-familiar unibody design?I think that all of these photographs are fake... and I mean every "leaked" iPhone '4G' photograph.
Why would Apple want to break the consistencies relating to the physical design of their products? Look at the notebook line-up; they look very similar.
Also, look at the iPad and iPhone (current); they also look similar.
Why would they immediately, and abruptly, halt this consistency in design?
Same with the jump from the iPod classic to the iPod touch. Same with the short diversion with the "fatboy" nano. There are plenty of other examples in Apple product design history.
While you are free to think of these as fakes, the number and frequency of highly similar "fakes" is most easily explained thusly: these are prototypes that are very close to the next-generation design.