It is more interesting to me to reflect on the comments from about 5 years ago that "ARM will never be in laptops, its a 'phone' processor."
That statement was both true and ignored the reality that if you wanted to put an ARM processor in a laptop you could add features and design it to work that way. Chip design is expensive of course, and so being a company like Apple really makes it possible to do this sort of thing as a 'risk' venture, but what surprises me is that Apple spent maybe $10B over the years developing an in house ARM design capability (after buying PA Semi) and here it is paying them some huge dividends.
If you compare that to Microsoft's efforts trying to use off the shelf ARM chips in the original Surface and now the Surface RT and you can really see the advantage of having the chip designers and the software designers depending on each other. That was true in the "WinTel" era when Intel and Microsoft were joined at the hip, but it was never the case for ARM CPU vendors who were more concerned about being in the next flagship phone than what ever it was that Microsoft was doing.
What an interesting alternate history if Microsoft decided to develop an in house production chip capability at the same time they decided to get into the hardware business for "real." [1]
[1] Yes, I'm aware they have done custom chips, the pixel/pen processor in the Surface is one such but they haven't really jumped in with both feet like Apple did, and certainly haven't had it front and center as long as Apple has.