Yes, but only if they keep it limited. I'd like to see a rival company be able to run OS X on their machines (pystar, anyone?), and produce some more niche products that apple doesn't seem to care so much any more (Mac Pro, really high end macbook pro, the works, as well as a cheap model). This is not likely to happen because it will cut into Mac sales, but if it did at least apple would have to keep innovating to stay near the top instead of just doing whatever they see fit. IMO apple hasn't really done anything huge over the past few years. Retina doesn't cut it for me with the soldered ram and non-upgradable SSD, as well as weak(er) graphics and a midrange processor. I can live without a thin laptop. I want the speed! Having a competitor would keep apple from controlling the market as much.
Of course, if they licensed it out to everyone it would be akin to android and windows fragmentation. Which, to be honest, is pretty terrible. Cheap "mac" boxes popping up everywhere with crappy screens and horrible, creaking plastic bodies.... 🙁