The FANGs already get custom silicon. Google has for years been working with other silicon, including its own "TPU"s, Amazon has just launched its own ARM stuff.
I think the customers here will be the usual data centre crowd, plus companies ramping up their own virtualisation efforts where it is still very much an x86-64 world. The move to the "cloud" has been extensive over the last couple of years, but it will come to an end at some point, as Intel alludes to (presumably from fewer requests and orders).
We will, hopefully, see a competition server market at one point but the barriers to switching architectures will remain high for a couple of years.
Biting the hand that feeds IT
