While the story may or may not be true, I cannot believe that Sony would have been able to sell Microsoft on the idea that some of their "PCs" were going to run MacOS. There was a pretty interesting example of how Microsoft responds when ASUS first tried to ship a x86 laptop with Linux as standard. (the EEEPC line) It resulted in a huge flap that spilled out publicly with things like ARM laptops being ordered off the expo floor at CeBIT and Microsoft bringing back a "dead" version of Windows XP for that particular model. But the bottom line was they went all out to keep ASUS from shipping a non-windows Laptop and that was in 2006 or 7. Five years earlier I expect they would have just threatened to pull Sony completely out of the OEM licensing program.