It's a flawed analogy, a kia isn't built nearly as well as a BMW, but a lot of us are actually running heavier duty hardware than is available in any Mac bar the Mac Pro (and that is made by the same manufacturers, my PC is all Intel and Nvidia hardware on an Intel EFI motherboard).
This machine will actually run vanilla OS X using the PC EFI hack (effectively Boot Camp in reverse) and the only thing that isn't natively supported is the on board sound - logically you could replace the BIOS emulation on this machine with Apple compatible EFI and the thing would install and run leopard straight from a regular retail disk.
Effectively we're talking about taking a BMW Engine, transmission and electronics and installing it in a custom chassis that's built just as well, if not better, and for half the price, the only difference is literally the badge on the hood.
Some of us don't see the point in dropping 3 grand on a machine that will be obsolete in 6 months (admittedly the Mac Pro isn't bad value at this time, because it only just came out, 6 months from now the same hardware will cost substantially less but the Mac Pro's price point won't drop - the old one certainly didn't), or dropping 2 grand on a machine that can't be upgraded and where a substantial part of the cost is in the display which you have to throw out when you buy a replacement.
I would like to see a system of Apple trusted partners, a handful of high quality manufacturers like Intel and NVidia who sell certified hardware with certified drivers (admittedly its hard to keep a straight face saying that, given NVidia's issues with Vista).
Apple don't have to support every hardware mfr out there, but if they would release OS X on specifically built generic systems, they'd take a HUGE chunk out Microsoft's market segment overnight, hell, they could release a $500 version of OS X for x86 and I'd buy it, it wouldn't be the first time they jacked up the price of software on non Apple hardware.
