Completely different things I'm afraid.
The processor used in the Xbox One is built specifically FOR the Xbone, games and apps for the Xbone are going to be made specifically and optimised for use on the console and the hardware inside, which is never going to change.
I'm no expert, but from what I've seen and experienced, PC applications are not built with any specific hardware in mind, but faster processors will run applications faster (layman's terms here, people) - for instance, look at WinZip benchmarks.
Many PC programs do not use 8 cores at all, hell, it's only now just becoming the norm that games use all 4 cores on a quad-core. It'll be a while until we see "Recommended: 8-core CPU" on the case of games.