ryubr: Instead of being a Mac zealot like the other posters
, I'll be nice and tell you some of the reason(s) why it won't work.
First of all, yes, OS X has a BSD core. But that's where the similarities to UNIX end. Much of the other stuff is all Apple-proprietary stuff, like QuickTime and Aqua.
One of the main reasons that Apple will not release OS X that runs on PCs is because of the legacy apps. The Classic Environment, which is the OS 9 emulator, would be non-existant on PCs, because you can't install it. Furthermore, Classic apps would not even work, because of the same reason. Classic apps were designed for the Mac before it gained a UNIX command line, so they wouldn't run on something like a PC.
Second, Carbon apps would have to be reprogrammed to run on a new processor other than PowerPCs. This is another problem, because you would basically still not be able to use any of the Mac apps out on the market.
Third, Apple is known for its outstanding high quality because, as Steve Jobs says, "We [Apple] make the whole widget." If Apple had to support all the PC hardware and the sound cards and the ethernet cards and the USB cards and the Firewire cards on the PC market, its quality would go drastically down the drain, and supporting all this would bring down the true Mac side of things.
So this is why you won't be able to run Mac OS X on a PC, and probably will never be able to.