In any case, it appears that Linux (and piracy) is a larger blip on Microsoft's radar than Apple, and it's not hard to see why. With an economy that's not doing very well, people will opt for cheaper products. Apple cannot offer those, but Linux and piracy can.Follow the link to the article, which has a copy of Ballmer's presentation slide.
Netbooks are the fastest growing segment of PCs, and Linux is a big part of that. Apple (so far, at least) doesn't have a netbook offer.
Linux is also a big part of servers in corporate computing centers. It's not at all clear that Microsoft will win the server OS war.
Hat tip: Slashdot.