No, I don't think Mac OSX will ever be able to run on the PC. The Mac hardware and PC hardware are different, as are the processors. There are programs that you can download to emulate a Macintosh. Just google around for some of them.
It might become possible through emulation in the distant future, but OS X will probably be obsolete by then. It would be somewhat like the 68k Mac situation today. BasiliskII and some other emulators can be used to emulate 68k Mac hardware to run upto Mac OS 8.1 on a PC, but nothing later than that. PowerPC emulation hasn't come yet, and probably won't come for a while.
The hardware being different isn't really a problem technically, but is probably the big reason. If Apple were to sell OSX to PC, who would want to buy a Mac? Sure some hardcore fans would, but the ones that aren't in it for the brand would probably rather buy three PCs instead of one Mac for the same price....
I wouldn't go so far as to say it'll NEVER happen. Like I said earlier, give it a few years...many years rather, at which time OS X will be considered a piece of obsolete junk. That's when you'll probably see an emulator come by. If the 68k Macs could be emulated, I don't see why PowerPCs never will be. It just takes time, and a lot of it.
If they kept going we must be up to 886 I suppose as the original pentium was nicknamed 586. I still remember my first pc a 386dx 32Mhz with 1MB of ram and a 40MB HDD!! It even had a special button to reduce the speed to 16Mhz for apps which couldn't handle the fast speed!