I feel like the iPhone is getting to the point that it's so thin that they will look more and more the same, like how iPads are going. If the phone gets any thinner, will the buttons be anything other than long skinny shapes? Hard to imagine going back to circles. Will the speaker and mic grills go back to the more detailed milling? Can't see it. It just has to get more and more simpler. Jony's ideal clean slate.
Every change they make will be in support of making the phone thinner, so I don't expect any return to the 4 or 5 style. and it'll make the 6 look old, meaning that the little plastic rim around the screen will go, it'll be just glass to metal. A buttonless home button like the new track pad. No metal insert on the lightning port. The shape is not so rounded. The glass still rounds as it does on the 6, but just cuts down and then back like the style of the MacBook line. Angular but still stubble curves. Sharp and curvy. We never had that. We only had curvy like a pillow, and angular like a brick. But nothing like the MacBook Air or the new MacBook. I think that would be beautiful.
And there will be a more stubble way of handling antenna lines. I think they are ok on the 6, I can't imagine a different design without adding vertical lines or asymmetries. The lines are the way they are now because on the top is NFC, below that next to the camera is cellular, and Wi-Fi is on the bottom. The very bottom piece is there for symmetry, it's just where the ports and grills belong. How do you have three antennas but want to make the entire back continuous metal (Johny's ideal vision), or at least look like it? As antennas get better, maybe you can use the camera area for NFC, if you only need a small place you can circle the camera area with a break, something that looks like it belongs to the camera but is really for an antenna. Have the Apple logo be another antenna, and a single line near the bottom for the third one. Or, if the camera trick sounds too far fetched, have one antenna as the Apple logo, and the others on the top and bottom. Each seperated by a classy, single horizontal break instead of the double deckers that are on the 6. I hope I remember this post and dig it up when that time comes around.