It's a dark day, Apple fanboys. Installs of OSX Leopard have led to the dreaded Blue Screen of Death for many Mac users (sure, it's sort of happened before, but the headline cracked us up...sorry). We can't yet be certain just how widespread this problem is, but an Apple thread on the topic has 263 posts with several incidents documented through the responses.
The problem appears to occur only for users who are upgrading from old OSs, which is just one more reason that any computer owner should pony up, backup their files and do a clean install on any new operating system. Whether or not the software "works" either way, clean installs tend to be less buggy over the long run. The Apple-using segment of the Gizmodo crew has performed both types of installs without incident—but you know how it goes—you'll be the unlucky one. [apple via fortune]
Update: As many comments have already pointed out, the error seems to be caused by Application Enhancer (APE). Happy installing.