Hell, P4s don't allow multiple CPUs. ANY alternative to not being able to upgrade some ****box comp in two years when you need that much processor to play ****in' Minesweeper is starting to sound good. AND everything ships with XP nowadays, which is basically Mac OS X with a vendetta against your memory chip and enough bugs to simulate a termite infestation on your hard disk.
And that's saying something, because I always have and still do consider buying a Mac, or in particular anything with Mac OS, tantamount to putting on stilletto heels, leather straps, and a feather boa and strutting around lisping about how you need a screensaver or your monitor will explode. They're the ****in' wood blocks of computers, and leapord-print ones at that. I prefer a chainsaw.