So to help me think about this gap, this essential philosophical difference between tablets and traditional computers, I imagine what things look like in the not-so-distant future. Let’s assume in this future, that both have essentially identical internals; the only differentiating factors are how they’re used, the externals, and what software they’re running.
Why would people of the future choose an iPad over a Mac, or an Mac over an iPad, if they’re both equally as capable? To even the playing field, let’s just say each Mac supports ARM® processors, touchscreens, Apple Pencil®, and biometric authentication. And let’s say each iPad supports mouse/trackpad cursors and any peripherals. And let’s also say Project Marzipan goes great and iOS and macOS® both make apps on the same platform. Now, we have a level playing field. What’s next?
Menu Bar
Let’s start with a softball. I don’t see Mac’s Menu Bar surviving. Designers have found much more intuitive ways of including all its functionality in the window UI with iOS. Because of this, if you install a macOS app which was invented within the last few years and you will see that its Menu Bar is very sparse, including only what is absolutely necessary, like Quit, Preferences, and Minimize.
Windows
Like… the windowing system, not Microsoft’s Windows®. Would iPad get them? Would Mac lose them?
I think neither. The most important thing is that on a 27-inch screen, it would be silly to restrict all apps to be fullscreen-only*, and on a 7-inch screen, it would be silly to allow any app to float in a user-positionable window.
So, obviously, there’s a point between these screen sizes which is a dividing line. I think that line will be the same as where tablets stop and laptops start. So no change here.
Peripherals
And what about peripherals? I must assume that iPad will eventually allow pretty much anything to plug-and-play into it, even if that might require a dongle.
Though if we’re saying that Mac excels at displays so large they’d be impractical to carry around, then those Mac could have lots and lots of ports for lots of peripherals, not only because they have the physical space for it, but also because it’s okay to tether it since it’s not going anywhere.
iPad’s main focus will remain its portability. Because of this, it’ll discourage peripherals to keep it so portable. So maybe only 1 port from now on. Not for courage, or for cost/space savings, but to keep the mindset that it’s the most portable computer form factor.
Mac, but a Tablet
If Mac gets touchscreen & stylus support, then will there be a small Mac in a tablet form-factor? It’s hard to say, but I think not; presenting a device as a primarily-touch medium means that you can, by default, do everything with it using touch, and that’s not true about Mac; lots of things simply require a keyboard andor mouse/trackpad.
Laptops
Alright, here’s a hard one: Will laptops remain in the domain of Mac, or of iPad? Like, if you have a clamshell attachment to an iPad which gives it a trackpad and keyboard, then will there still be a reason to release dedicated a clamshell Mac with that keyboard and trackpad?
I think the larger of these will stay in the domain of Mac, that being the 15-inch-class sizes. Again, it would be silly to force all apps to be fullscreen at 15 inches. That said, I can easily see 12-inch-class laptops just being “convertible” iPad devices with accessories. Also, Apple should totally call that iBook®.
Summary
Mac excels at large displays, and iPad with small ones.
Smaller MacBook® devices disappear, with iPad taking over that size class as “convertibles”. Large MacBook devices remain.
Mac excels at multiple peripherals, and iPad stays away from them to maintain its ultra-portability.
Mac avoids the tablet form factor, and iPad keeps it.
And now a table
Because I like tables, here are my predictions as a table of eventual features: