What do you know….it appears someone actually got Windows XP to install on an iMac. To “prove” it they’ve made a video which you can check out here. (Click on the mirror link within the article.)
The video shows the installation and initial running of XP. It’s a little bit like a UFO video, lots of jittering and zooming in and out, but it’s worth it. The video appears to be legit.
From what I understand the developer is translating BIOS calls to EFI. It’ll be interesting to see where this leads.