On the other hand, although the ISA is public, I'm guessing the whole boot-process & platform will become more and more closed as apple moves towards custom chips all the way down.
Is there any chance you can still run linux on mac hardware in 5 years ?
You make a very good point. The dominance of x86 is largely because it forms the long-standing open PC platform, which while Apple and others have been trying to remove "legacy" features from and lock down for a long time, still remains quite well-documented and open in comparison to smartphone/tablet SoCs that have next to no detailed public documentation at all.
Maybe they go to three architectures in the app store, or maybe they only support ARM after 32 bit is dead. Which works out nicely with the recent deprecation of 32 bit apps.
Also, given the Intel OS X project was cooking long before they announced the transition, it’s likely safe to believe that full blown OS X on ARM is already running somewhere in a lab at Apple.
No idea where all the creative types will go if that happens. Apple could indeed be shooting themselves in the foot on this one.