I know the PPC vs Intel debate has been raging forever, but I still have to jump in and point out that a Macintosh with "Intel Inside" (or AMD for that matter) does not equate to Mac OS X running on any old PC from Dell, HP, whatever. That's my biggest beef with people that are against the x86 architecture for Mac. Don't throw the baby out with the bathwater.
I totally support Apple in killing the clone market. Let's face it, 5% (or whatever) is not a big enough market to share with anyone else in this day and age. I don't want them to support Mac OS X on other hardware. I absolutely want Apple to stay in the hardware business and continue making "insanely great" computers for the rest of us. The new iMac G5 is great. Not without flaws, but great nonetheless.
However, I think that Apple would get a lot more "bang for the buck" if they were to use AMD processors with HyperTransport, etc. on their own proprietary motherboards that they design to only work with their OS.
I also think there would also be a huge benefit in designing Virtual PC to run with "native" hardware underneath. You couldn't install Windows on a Macintosh, and you couldn't install OS X on a PC, but you could install Virtual PC on a Macintosh to run Windows at near native speeds. Apple could withold the secret sauce to prevent anyone from creating a Virtual Machine that would make a PC look like an x86-based Macintosh.