The other major number that caught people's attention in the recent Apple earnings call was the drop in gross margin (47% to 38% YoY) which is mostly explained by the iPad mini but definitively hints at lower margins in their future. This is a normal part of any suitably competitive market and should be expected; what might not be however, is why the post PC components of Apple's future might not currently be as well insulated from margin pressure as prior software platforms.
The theory goes something like this: Microsoft Windows was able to maintain an exorbitant margin on its Windows and Office franchise because of the combination of feature lock-in and network effects. Everyone focuses on the latter because it is easier to see: more people using Windows means that file sharing is easier as is the size of the platform target for developers which enriches the platform and makes it harder to choose an alternative. But the former is equally important in my view and can be summed up in a statement I once heard about MS Word: "no one uses more than 10% of Word's features but for just about everyone, it's a different 10%."
Compare that to any of the utility apps on iOS/Android that have more than 10M users— if everyone used just 10% of those features, you'd be using fewer than one feature of Dropbox or Evernote. Or put another way, these apps on iOS are super thin by design and new apps seem to be getting thinner. This has two benefits for app creators: first, it is easier to port stuff when all you are doing is rewriting a view layer for the specific target platform, and second, you can leverage your back end services for the real heavy lifting (such as Evernote's awesome OCR) which means that you are basically out of version hell management with 90% of the iceberg that is your app.
For the platform provider though, the world is a much uglier place. Right now, there are no significant apps on my iPhone that I couldn't find on Android or Windows Phone. And the OS provided apps are less and less relevant every day. Having already replaced music, email, the address book, and data sync, the only app truly keeping me "stuck" is the Apple Remote app and only primarily as a parlor trick.
This may dramatically affect platform differentiation/profit taking in the future (or at least completely shift the game to a hardware fit and finish one), but there is also a obvious way out. If Apple were to begin using its cash hoard to buy some of the better services of the post-PC era and closed them off of all of the other platforms, they might have a better reason to maintain their high margins. I say buy because of the lessons of iCloud and Dropbox: everyone thought Dropbox was a feature until iCloud proved to be its poor country cousin drunk on Moonshine and losing your files en route to the cloud, but they might still have an awesome service or two in house. For instance, knocking off Spotify seems like a no brainer (they are the largest licensee of music in the world after all), and working on radically simpler, Apple-esque music consumption experience when the world's catalog is at your fingertips seems well aligned to what the company that brought us "5000 songs in your pocket" could do well.
The other potentially very interesting vector for sustained differentiation would be enriching iOS as a more full featured content creation platform. Given the massive shift away from PCs to tablets that even they have felt, it seems that giving app developers compelling and differentiated APIs that allow for more expressive creative or work tasks and simply staying one or two tricks ahead of the competition might help that. This is after all, the company that gave us an API for tracking 10 fingers down on the glass first (and Siri, is neither forward looking enough, nor a core strength's of Apple's given their mediocre execution on the server side).
Who would have thought that thinness could be such a curse?