I just read this post on Think Secret about the new Intel-based developer Macs:
Sources have indicated that Apple will employ an EDID chip on the motherboard of Intel-based Macs that Mac OS X will look for and must handshake with first in order to boot. Such an approach, similar to hardware dongles, could theoretically be defeated, although it's unknown what level of sophistication Apple will employ.
The thing is though, really, who cares? I have to admit, I might spend a weekend day trying to get OS X to run on a random PC, if I've got nothing else to do. (Which doesn't happen very often, nowadays.)
But, that's just because I'm a nutter unlike most people--and even I'll be buying a new Intel-based Apple computer eventually, anyway. As for everyone else, it'll likely be made just hard enough to be worthless to anyone seriously trying to get anything done. It'll be a curiosity, nothing more--and certainly nothing to endanger Apple's bottom line.
It's the whole package deal, stupid. And it seems a bell-curve-ish theory of DRM: You won't get absolute 100% control over what happens to your stuff in the wild, but you'll get most of it or at least enough to matter.
It's also somewhat reminiscent of hidden iPod directories and iTunes FairPlay: Just make it hard enough to not be worth it to anyone who doesn't have time to put up with crap. And, make it just hard enough that anyone who does have an inclination to deal with crap has to continually tweak their hacks to keep up.
While I do despise DRM barriers in principle, at least this seems less odious than most. And, well, there are plenty of other much more tinker-friendly operating systems available for plain vanilla PCs.
So, in the end, who cares? Buy a Mac, or don't buy a Mac. Or, enjoy perpetual tinkering for its own sake. But, don't expect to get a seriously usable OS X system on anything other than what Apple supports.