Related link: http://ezine.daemonnews.org/200306/dadvocate.html
One particularly interesting hypothesis:
Linux source code is freely available. UnixWare source code is not, even less than many other proprietary UNIX implementations. Thus it would be easier to copy code from Linux to UnixWare then from UnixWare to Linux.
Lehey also has a page tracking the debate.
Will the SCO Lawsuit cause a run toward BSD operating systems?