Apple does nothing "on the cheap". Even their packaging cost more than just about anybody else out there.
Apple is pushing smartphone and tablet SoC tech harder than any other maker, you can bet your money that Apple will be one of the first companies to use 20nm SoCs.
Agreed. Battery life is an important metric to Apple and you can rest assured that Apple will absolutely be the first in line for 20nm.
[major tangent incoming]
Cost is also not a factor for apple. In fact, looking at their BOM I would not consider any of their products cheap. Now, don't get me wrong, Apple products cost more - but to many folks, it is worth that cost. But the main point is, there is nothing cheap about Apple products. They focus on the user experience and intangible metrics and making it "gel" together far more than any other company out there, and it shows. Now in terms of smartphones, there are a lot of smartphones that are at parity with Apple nowadays. But tablets? Ultra portable computers? Apple IMO has the best products out there. Every ultrabook i've tried has compromises - HDMI that doesn't go higher than 1080p, barely functional trackpads, terrible battery life, idle that doesn't properly work, I could go on. These types of issues usually aren't issues with Apple because they focus on perfecting the user experience.
I've said it time and time again. The best hardware is worthless without the user experience and software to back it up. Apple understands this. Nvidia has also taken que of this, IMO....I have noticed that nvidia puts a _lot_ of effort into user experience and the intangibles just as Apple does, and I believe that is the right approach to creating consumer loyalty. Again. Hardware is worthless without excellent software.
Anyways. Yeah, Apple will be one of the first with 20nm and they certainly won't cheap out in that respect. Battery life is huge for apple products.
It's also good that nvidia has apparently reserved 20nm wafers as well, from what i'm reading. Although i'm not sure if that is for Maxwell or Tegra 5.