A main reason they might be switching also is because they've gotten screwed over twice in the past for not doing it. I think they're sick of MS and IBM, so they're trying to screw both of them.
Also, it would probably be alot easier to run Windows on your Pc-based mac than the other way around. Though, the whole ID thing was tryed and it didn't work, it's called the XBox. And it's gotten hacked a buttload. For Mac OS to run on a PC though, that's a bit of a stretch. It'd be an ugly hack cause Apple will surely go with Openfirmware, not any PC standard BIOS. On top of that, the mac running on a PC would have to support alot more: IDE/SCSI controllers, PCI/AGP/AMR controllers and drivers for all the different types of everything that'll go in a PC. They do that now, but unless you have a pc w/the same hardware as a stock mac, you'd have to figure out all that crap. I'd think that would be harder than cracking those IDs.