The departure of Scott Forstall as the man in charge of Apple's iOS efforts seems to have many reasons behind it. Much of the coverage is focusing, rightly, on the likely negative factors, in particular Siri's tepid performance and the Maps debacle. Also, Forstall's mania for skeuomorphism.
But there's more to it than that.
Forstall may have been, in John Gruber's words, an "obstacle to collaboration within the company". Indeed, the Apple statement about the changes is clear that they "will encourage even more collaboration between the company's world-class hardware, software and services teams".
What might those changes look like? I suspect they will involve the fusion of Apple's desktop and mobile operating systems. Yes, iOS is already based on OS X, but I'm talking about the two officially becoming one operating system, with one UI, at some point in the medium-term future.
The two key post-Forstall job redefinitions were for Craig Federighi, previously in charge of OS X but now overseeing iOS as well, and Apple design guru Jony Ive, who is also now in charge of 'human interface' across the company.
According to Apple, Federighi's new role "brings together the OS teams to make it even easier to deliver the best technology and user experience innovations to both platforms". The company is a bit less clear about what 'human interface' means.
Whatever it means, though, iOS is long overdue for a UI revamp, and Forstall's departure makes that all the likelier.
Now, let's put all this in a wider theoretical context — specifically, a context that also involves a successful Windows 8.
Much of the Windows 8 drive is around touchscreen laptops. Steve Jobs famously scoffed at the idea, saying it would be an ergonomic disaster, but then again he also scoffed at the form factor that Apple has just embraced with the iPad mini.
Touchscreen laptops, or convertible tablet-laptops that allow multiple form factors, may or may not take off. I'd say they have a good chance — the first wave of touch-enabled Windows 8 notebooks includes some very attractive hardware, and Windows 8 is a very touch-first OS.
And, from the very beginning with Windows 8, Microsoft's treatment of tablets and desktop computers involves one OS — well, two if you consider the 8/RT split, but that's a split along processor architecture lines, rather than form factor, and will be irrelevant to many consumers.
So that's one thing: Microsoft could make consumers quite at ease with the idea of using a common, touch-based interface across mobile and desktop devices. That in itself would leave Apple's bifurcated strategy looking rather outdated — if people get used to manipulating stuff on their desktop screen by hand, just as they do on a tablet, they won't be satisfied with a non-touch screen for long.
And it would just be silly for Apple to develop a second kind of touchscreen interface for its desktop products.
The 'human interface'
But the other aspect of Microsoft's offensive is one we've not fully seen yet. The current crop of Windows 8 tablets and PCs is missing a killer feature that we know Microsoft is already working on: Kinect for PC.
Although it currently involves the use of a peripheral, I would be stunned if Kinect did not become an embedded feature in Windows 8 devices, at the very least in a future iteration of the Surface. How would it work? I'm not sure — I'm not a 'human interface' designer — but the possibilities for new gesture controls are extensive to say the least.
That, I suspect, is where Ive's new responsibilities come in. In the realm of the 'human interface', Apple is playing catch-up. Microsoft is way out in front, having used the Xbox 360 version of Kinect as an astonishingly successful testbed.
Now, put yourself in Apple's position. Even without considering the issue of Apple TV, if you're developing new, perhaps even post-touchscreen interfaces, do you want to do that in two separate streams, or one? Wouldn't it make so much more sense to unify the two platforms with a consistent UI? To do otherwise would likely involve teaching users two similar yet non-identical gesture languages.
Of course, all this remains theoretical for now. Jobs may have been right — perhaps people will shun touchscreen notebooks. Maybe tablets will totally obliterate the desktop market.
But I doubt it. And, if Apple still has to maintain both mobile and desktop lines in future, it would be in its best interests to at least unify the interface. The ingredients are all there for it to do so, and now the right people have the right responsibilities to make it happen, too.
It's easy to see Google as the competitor that drives the most development in Apple's OS strategy these days. Chances are, that key rival will soon turn out to be Microsoft instead.