I think the point of Apple going Intel is twofold. First just to run on hardware that CTOs are familar with, gaining credibility by this fact alone (silly but true). But most important resonates with David's thesis. Apple plans to show that moving OS X from platform to platform can be done with virtually no problems at all, establishing OS X as the clear development path into the future regardless of advances in processor technology. Intel wants to make (and sell) more advanced processors that abandon the x86 architecture. OS X can not only serve as the OS in these cases, but people will have faith that Apple can do this in way that doesn't create much headache. If AMD jumps into the frey, all the better. Windows Vista becomes an interesting historical note. Microsoft comes out with Windows Lux (Linux Edition) to save some share of the market.
PowerMac on Intel, the Beast Cuts Loose