Thanks to Parallels Desktop, an $80 virtualization solution that will sell a million Macs all by itself, every Intel-based Mac will run every 32-bit x86 OS, from DOS to Longhorn Server, from FreeBSD to Suse Linux Enterprise System, at (truly) near-native speed and with no need to reboot to switch OSes.
My son just got an Intel iMac, and installing Windows XP is in the cards for me as soon as I get Boot Camp and/or Parallels set up. But the thought of just as easily running other x86-based OS'es hadn't occurred too me. Cool!