OS-X on Intel read-me was given to me by Joel last week - we've got a pal who's got it working on his PC and Joel has pulled the ISO so we can try it here. I'll report back on it but there are a couple of things that peaked my interest. Firstly John Dvorak's column on PCMag.com;

There is no question that this would be a boneheaded move, and as I see more and more chitchat about the possibilities, I'm now convinced that this is all a publicity stunt and the Apple community is being used—once again—by the company's marketing department.
That said, I will admit that the possibility does exist that Apple doesn't want its OS in the wild, since it could potentially hurt hardware sales. At least that's the way the company might see it. This assertion does assume that the Apple marketing department is brain-dead....

The implication is that it slipped out of Cuppertino far too easily. This is stealth alpha-testing by Apple!
The other article I saw was in PCW and something there rang true;

.....forthcoming Intel-based Mac OSX operating system on a non-Apple PC. They say on some PCs it appears to run faster than the version on current G5 Macs

This seems to be borne out by Avid who have always maintained it's easier optimise for PC compared to G5 - see a previous blog entry here.