I have added more startup code to make it less likely to fail to load.
The source is covered by APSL, so modifying it is legal and here is the source posted to comply with that license.
Edit: 31 July 2006 - Updated kext and source. The keyboard now works without a mouse. More reliable, the kernel debug option is now off.
Kext: ApplePS2Controller.kext.zip 284.42KB 30436 downloads
Source: ApplePS2Controller.zip 95.58KB 6436 downloads