AMD also has ARM irons in the fire[1].
I was trying to hint that AMD might make some weird hybrid x86/ ARM beast that could have the advantages of ARM much of the time, but could run x86 native. I'm not sure that's even possible.
AMD might do well in a post x86 world. It's just a broader playing field.
I'm sure it could be done... but probably would have some interesting effects on software (unless you do full x86 emulation on the ARM cores... but then what's the point).
It's far more likely we'll start seeing ARM processors with hundreds or thousands of cores in the server market first. These would be particularly interesting to virtual server providers like Amazon, Google, Digital Ocean and others.