If there's one rule of thumb, it's don't count intel out of the game early:

Intel is shrinking it's process to an anorexic 14nm, and heavily targeting Atom:

http://www.anandtech.com/show/4345/i...t-atom-in-2014

What they're expecting is

I have an idea, why not drop x86 for something more space efficient before it's too late? Even if only a contingency, a more efficient instruction set would put serious heat on ARM. I expect the trick would be to fill in the software gap by providing compilers for linux.