DailyTech's got the story, but the actual winxponamac.com site is hammered at the moment, so don't even bother trying to get to the source just yet. DT's also linked the video from Engadget (.mov).

" A programmer named Blanka was able to get past all of the EFI issues and has provided a working solution to natively run Windows XP on an a Mac. The programmer can now claim the $13,854 prize thanks to his video of the installation and booting of Microsoft's ubiquitous OS on an Intel-based iMac."