@ several
@ Daniel B.: '[..] then saying some time after that "Intel is the way!"' -- well, there were 8 years between the introduction of the G4 and the switch to Intel. Switching back to PPC within within 2 years after going through a huge amount of trouble to switch to Intel in the first place might look a little ludicrous. Whereas at the time it came out, the PPC 7500 (aka G4) actually beat Intel's chips lengthwise and broadside in performance per watt, throughput per cycle and actual just plain performance in practical applications like image or video editing.
@ Geoff: Good point, which I had overlooked. That might really be an interesting thing to observe -- though AFAIK the current line of XServe RAIDs is not manufactured by Apple but rebranded OEM ware.
@ Niall: Compared spec-for-spec, I find Apple not all that overpriced -- no, really. I guess it depends on where in their product life cycles you compare prices, but at least with the notebooks, they're not all that expensive if you compare same-spec machines from the likes of Dell, Acer, Toshiba, et al. (I last compared about half a year ago, then decided to install Linux on a MacBook Pro because it was about 250 quid less than what the others were offering me at the time in the same performance range).
But that aside, I agree about the "cool" factor -- plus, since they already have the well-tested PPC version of MacOS X out there anyway... *shrug* how could they resist? And the bonus is that MacOS X scales pretty well with the number of cores involved (it's BSD on a Mach kernel after all), so they actually _could_ go for the big iron if they wanted to. They already have one PPC installation in the upper ranges of the top 500 supercomputer list after all.
Disclaimer: I am not a fanboi of any hardware or software supplier. I don't drink Kool-Aid of any kind. But I can still be fascinated by developments...