Re: The cost of broken x86 is already significant and rising rapidly...
What's interesting about whether Intel/AMD can adapt is that they've already done it once with x86-64, but in doing so they made a lot more cruft. They might be able to offer a stripped back more efficient better validated DC focussed x86-64 variant, but it'll be tough for them to market it. Case in point Xeon Phi's long twisty genesis.