If Apple wants to dominate the PC market, they need to release Mac OS X for PC's. Every PC user once in a time wanted to install Mac OS X on their PC's. We can see that clearly looking at Hackintosh sites. So, I believe Mac OS X 10.10 should be the first Mac OS X that is available for PC's, for free. This will threaten Microsoft's long lasting Windows dominance. Something that neither SteamOS, nor Linux can.