If the new model has a larger screen, 5K would definitely be insufficient.
I'm a photographer and and constant user/developer of image manipulation software. I edit every shot. I don't need 5k in a monitor; if I need a full-image overview, I can have that, zero perceptible time. If I need to look at pixels, same thing. Or anywhere in between. I do *not* need to be squinting at a monitor in order to resolve detail. I value my vision too highly. And at these resolutions, you don' t squint, you can't see it. And I have extremely high visual acuity.
Higher (and higher) resolution makes sense in data acquisition. Once you have it, you can do damned near anything with it. Even if you exceed the MTF of the lens, you get the advantage that while the edges are smoother, they now start in a more accurate place, geometrically speaking. It can be thought of as like old TV luma; the bandwidth is limited, so the rate of change has a proportionally limited slew rate, but the phosphor on an old B&W monitor is continuous, and you can start a waveform anywhere (horizontally) with luma, to any accuracy within the timing of the display, which can be pretty darned high. So things tend to look very, very good as opposed to what you might expect from naively considering nothing but the bandwidth. It's not like a modern color display, where the phosphor/pixel groups serve to sub-sample the signal no matter how you feed it in. But that advantage goes away when the subtleties exceed your eye's ability to perceive them. Or you have to strain/hurt yourself to do it.
So anyway... any single one or combination of these three things would motivate me to buy more new Apple hardware. Nothing else:
o A Mac pro that is self-contained -- installable, replaceable drives, lots of memory, replicable display cards. The "trashcan" Mac pro is an obscenity. All it did was send me to EBay to buy used prior model Mac Pros. The trashcan isn't so much a wrong turn as it is a faceplant.
o A Mac mid-tower that can have hard drives installed+replaced and at least 16gb of RAM. 32gb would be better. Doesn't have to be that fast. Real gfx. I know, mythical, not probable. Still want it, though. Actually, I want several. :/
o A multicore Mac mini with a real graphics card, 8gb or better ram, network, USB, HDMI and audio ports.
I have uses for all those. Failing that, and in fact that's my expectation, more fail -- I'm done with them. And I have no use whatever for "integrated" graphics.
What's annoying is that just about when they finally managed to a get a stable OS with most of the features I like and want (and the ability to get around the stupid features like "App Nap"), they totally borked the hardware side. I just can't win with Apple. Sigh.