iPhone 7 Design
It's still early but there's a very good chance the iPhone 7 will look different than the iPhone 6 and iPhone 6s.
iPhone 7 rumors are already pointing to some potential changes to the iPhone's design. One huge rumor claims that Apple will be offering a waterproof iPhone 7 that comes with a new frame and brand new casing materials.
With the addition of the Touch ID display technology inside the iPhone 6s, analysts now believe there's is a 50% chance the iPhone 7 design ditches the physical home button on the iPhone for the first time.
Gene Munster from Piper Jaffray also claims that "Apple would need to move the Touch ID reader to potentially the side of the phone to remove the home button."
Respected KGI Securities analyst Ming-Chi Kuo also claims that the iPhone 7 will be the thinnest iPhone yet. He believes that Apple will slim the iPhone down to thickness that falls somewhere in between 6.0mm and 6.5mm. This would put it in line with the iPod touch.
Apple typically offers a dramatic redesign every two years so there's a good chance that the iPhone 7 design will be a lot different than the all-metal designs found on the iPhone 6 and iPhone 6s.
Whether or not those changes include a water/dust resistant design and a missing home button remains to be seen.