[majewsky]

If Apple switches Macs to ARM this or next year as rumored, all the interesting problems w.r.t. chip design must have been solved at this point.

[culturestate]

You could make this same argument for any sufficiently mature architecture, but the reality is that there's always something new around the corner. I can't imagine the processor in an eventual ARM-based Mac Pro will look much like the one in the first ARM-based MacBook, you know?