|In reply to Comment 16 (itix):|
See the one's I listed there's a 133Mhz card and they're the same shape for multiple systems. While I realize you won't be able to use every connector. It would make some sense to make the PPC motherboard (PegasOS or AOne) compatible with the PPC modules that Apple's using instead of creating something else.
My only thought would be Apple has the rights, or another company, and the usage costs to do so would be high.