I think the parent makes two good points. Apple gains from this and people will indeed pay more to avoid Vista.

My anecdote:
I bought 3 new computers for the house last year. The desktop for myself was my chance to escape from dual-booting and run a purely Linux system. I'd been happy enough with Ubuntu finally to do it, and plus I could afford system two... the windows computer to appease my wife who had always complained bitterly (and still holds it against me) when I'd tried to get her to use Linux. Since I just got her a cheap system, it didn't have an XP option. I figured she'd be happy with the shiny Vista interface. Only I had to upgrade the store bought - pre installed with Vista system with more RAM in order to get it to function.

System 3 was a laptop that we would both use. After much debate, I managed to talk the Mrs into letting me get an Apple. She was very apprehensive, not being the sort that takes well to technology changes, so is what I consider to be an "average consumer". She didn't like the Mac at first, and to be honest, it took me a bit to figure out how to get the default settings fixed so that I could right-click.

Long story short, she's been exposed to all 4 OS's now. When her company got her a work laptop, she requested a Mac. Her IT shop refused to support Apples so she made them downgrade a Dell to XP from Vista. I'm betting the time it took their IT shop to reload OS and get it working (taking into account their 'competence') cost her company a good bit more than $150.

Even though she occasionally uses the Vista machine at home, she doesn't like it and she uses my MacBook Pro more. I anticipate that there will never be another Windows box in our house. Thank you, MS for giving us Vista.