If Apple's going to use this type of immature politician-level advertising strategy, at least perhaps it should ensure that its OS can run on any brand of computer. A lot of people cannot afford macs ($600 Dells are quite popular)
(And before you say: well macbook's are affordable: well, if you're even considering buying a $600 computer, $450 to upgrade to a macbook is A LOT of money. Also, the $600 computer people probably won't need iLife and Garageband++, which is often used to justify the higher price of macs).
If they want to steal Vista's thunder and customers: Release Leopard and stop whining. And to play devil's advocate for a sec: If

REALLY wants to compete with Microsoft: try releasing an OS compatible with all computer manufacturers so that the other 95% at least has the OPTION to install it --->
Which takes us into a coooooompletely different discussion on some other thread I believe.