useless and expensive Sony Vaio with built-in Vista
From personal experience, that's where the main problem probably was. Vista was pretty bad though, as well. I really like Win7, and I had some not awesome experiences with Mac OSX at my old school with 10.5, the machines were constantly hanging on stuff as simple as running a web browser and MS Word. I am strongly considering an Apple notebook as my next notebook computer, because I would like to have access to all the major OS platforms.
I don't love Apple, but I think they're okay, I don't love MS either. I'm not surprised that AAPL has gotten richer than MS, they make a pretty penny on hardware sales, and iTunes is the biggest music buying platform out there. I personally don't know anyone who doesn't use iTunes at least part of the time when they buy music.
I don't know a lot of people who still use XP at home, and I only know one person who for sure still uses Vista, simply because it's fine for him, and he doesn't care enough to upgrade for the ~$100-150 it would cost him. One of my friends is a diehard XP fan, but he finally switched to 7 when his dad got him a RAM upgrade and new GPU for christmas, and then got the family pack of Home Premium upgrades at Fry's. He wouldn't have bothered if he didn't want to use more RAM or hadn't gotten 7 essentially for free.