Without any third-party apps. And without Bootcamp.It will be a Mac, so macOS.
It would make sense if they did that, given that iOS and OS X are very similar in terms of some of ther respective codebases.Closer to Mac in UI (it is likely to be a traditional mouse/keyboard computing form factor) unless Apple does a screeching U turn on touchscreen laptops. Not to say it couldn't also be very different - OS X was made from the ground up for the Intel transition, this could well be 'macOS 11', rather than just macOS 10.16, a largely new OS, sharing a lot more iOS code, but with more Mac OS X features, and the traditional UI on top.
Any idea?
Not to say it couldn't also be very different - OS X was made from the ground up for the Intel transition
Without any third-party apps. And without Bootcamp.
DOA look.
There's no technical reason why Mac OS on ARM should look, feel or work any different to Mac OS on x86. Its 2020 and if an end-user needs to know what CPU their machine is using then someone is holding it wrong.
Any change, any further iPadOS-esque lock down or restriction is purely a marketing decision for Apple.
Apple seem to have a successful and separate product line with the iPad Pro targetted at the "2 in 1"/MS Surface market, so it doesn't make much sense to turn the Mac into, basically, a big iPad with a keyboard when they already make a big iPad with a keyboard.
...on the other hand, if Apple did want to turn the Mac into a big iPad with a keyboard, they could do that tomorrow without switching to ARM.
OS X was made from the ground up (starting with NeXTStep in 1989 initially running on a 68030, later SPARC, PA-RISC and Intel) as an implementation of not only Unix - an OS founded on source-code level compatibility that is pathologically hardware independent. OS X also allowed Apple to easily spin off a mobile-optimised version for ARM (iOS). Anyway, OS X development started with the purchase of NeXT in 1996 and, at the time, had to be ported to PPC, so while the potential for moving Macs to x86 (or, at the time, SPARC, Alpha, or even ARM) may well have been a selling point, the actual Mac Intel transition was still a long way off... The priority then was that Copeland - the planned successor to MacOS - was an epic fail and Classic MacOS was long past its sell-by date.
Well, Bootcamp as we know it would be over - although Bootcamp for ARM Windows would be technically possible. Third party apps, though... huge swathes of them will just need the developers to tick the 'ARM' box in XCode, re-compile and test, many of the likely problems will have already been fixed by the 64 bit transition, while tearing out any x86-specific optimisation and replacing it with calls to OS X frameworks is progress, since it means they will be able to use future hardware acceleration features that Apple may include on their custom processors.
Apple have done this twice before at times when it was far more likely to run across lovingly hand-crafted assembly language or hard-coded AltiVec/MMX instructions in source code. They've spent the last several years promoting hardware-independent code via their app store guidelines which will help.
Some of the big pro Apps with their huge ecosystems of fourth-party plugins may take a while to get ported - but if Apple have any sense they'll get that ball rolling months before they actually release ARM-based macs, let alone start discontinuing the Intel versions of higher-end Macs (I don't see them dropping the Mac Pro next year unless its a flop).
Steve did say just as the classic MacOS lasted Apple about 20 years, the UNIX based Aqua interface would last about 20 years. Well, it’s been 20 years.
That would be an awful reason to change it. If someone comes up with a brilliant new user interface paradigm that isn't just form-over-function then fine - but have the better idea first, then decide to junk the old UI.
iOS is justifiably different because of the very different demands of a touch-only handheld interface with limited screen size.
Even if we do see ARM-based Macs in 2021, there's no guarantee that every new Mac model will be ARM (will there be an ARM that can replace the Xeons in the new Mac Pros??). And even if they went 100% ARM by 2022, they'll still have to crank-out Intel-compatible versions of the OS for another 6 years or so to support legacy hardware.
So... Will they make a dramatic change in the appearance of the OS? That'll be purely a marketing decision. I wouldn't bet money in either direction on that question, but I suspect that as long as they're selling iPad and Mac as separate product lines, they'll maintain some differentiation. Basically, there is a difference between features/apps that support Apple's ecosystem/services business (iCloud-based features, media products), and those apps and functions that are closer to free-standing. There needs to be high levels of functional duplication/similarity in ecosystem/services-based features and apps, but the look of the two OSes can continue to march to somewhat different drummers.
Functionality? I don't see them dramatically simplifying things, either in the UI or under the hood. There are users that demand that functionality, so why would they alienate the people who are willing pay much more per Mac than they would pay for an iPad?
I seriously doubt they would bother to move to ARM if they were planning to cripple Mac as a platform within 5 to 10 years. Their goal with ARM ought to be to reinvigorate Mac - custom silicon with capabilities not shared by Intel, with features and improvements rolling out on Apple's schedule, in configurations matched to Apple's requirements. If they don't do a better Mac, then why bother at all?