So, we're not quite a quarter of the way into the 'iPhone cycle', but you can be sure that Apple are working hard on the next generation of iPhone and, according to a MacRumors post, we can expect to see a new camera arrangement of the first time since the iPhone 13.
Specifically, according to an 'anonymous source' the iPhone 16 will see vertically aligned cameras, perhaps more like those on the iPhone 12, or maybe even in a single 'pill' like the iPhone X. (At the moment the iPhone 15 features the camera arranged diagonally inside the square.) To their credit, MacRumors do pick some good sources. They have also created some image mock-ups, including the one above, to illustrate that concept. The colors, however, are apparently those being considered at Apple for the iPhone 16, codename 'DeLorean'.
There was a lot of discussion about the button layout before the launch of the iPhone 15 Pro, which boasted an Action Button where its predecessors had sliding mute switches. This will also, apparently, be brought down the range to the iPhone 16 – hardly a surprise since it is clearly cheaper to manufacture than the switch and poses less of a threat when it comes to water and dust ingress.
Button projects have also looked at merging the volume button into a single long rocker with no moving parts, just haptic feedback – Apple's internal name for this was the Bongo project, but that seems to have been abandoned. MacRumors cite 'unresolved technical issues' but I'd be tempted to say that people just didn't like or trust the technology. Seriously, what happens when you need to do a reset?
Not that Apple has completely given up on the idea; a capacitive capture button (project Nova, since you asked) is on the cards for at least the iPhone 16 Pro. Apple has gone as far as working out where in the casing to move the antenna to make space for this touch-sensitive button.
On the front, with the dynamic island, and at the bottom where the USB-C port is no changes are anticipated.