You can see obviously that the trends that smartphones created, especially iPhone, are stirring the evolution of the PC (and yes mac IS included as a Personal Computer).
If Apple manages to keep up with the iPhone sales, they can offer a great sandbox solution to the market, e.g. get those files on all your devices by default, no configuration, everything works out of the box, get discount on those purchases from our company e.t.c. they can force their customers to buy iMacs, Macbooks and so forth.
I believe it is not the transition from PPC to x86 that boosted the iMac and macbook sales, although intel had a greater chip in the mobile market, but the fact that the Apple trend rose the same period when they released the iPhone.
As a developer, products like the ones from Apple do not cover my needs, I like to tweak around my devices, add features(mPCI-e cards, extra drivers or batteries, or 2nd VGA , I know it sounds crazy but the Ideapad series offer that) and I use exclusively Debian, so there is no reason to get a system that it's h/w locked and it's software is designed for FB and twitter users.