The level of misinformation and blatant, all-out lies in some of the above answers is absolutely STAGGERING. I'll do what I can to correct some of it for you.
Jamestl: I'm sorry you had such a traumatic experience outside your comfort zone.
Python: Mac viruses do exist. You know why Mac users' worlds aren't crumbling away as a result, like Windows users are used to? Because OS X isn't the hobbled-together, sado-masochistic engineering nightmare that Windows has been throughout its existence. If you really want malware to be able to do anything bad on a Mac, you have to explicitly give it permission to do so. Read that again. You have to give it permission, or it can't infect its way out of a paper bag. You say you'll be using Vista? I'd say welcome to 2001, but Microsoft hasn't even caught up that far yet in any but the most superficial ways. Here's some light reading.
(links seem to generate errors here, will try to add 'em back in) (edit: put them in source — legit links, I assure you, it's just throwing Error 999s at me left and right when I try to paste the whole thing in)
Villanim: your arguments against Macs are almost as weak as your definition of what's real and what's not. Almost. There's so much propaganda and Stockholm syndrome clogging up your post I'm hardly sure where to begin, so I'll take you point-by-point.
>Not as secure as Windows (more security releases then Microsoft, and Apple takes longer to patch their holes)
That breaks down when you realize that much of OS X is open-source, which means that anyone can bring flaws in those projects to Apple's attention, or even fix them themselves. The fact that they patch more holes than MS doesn't mean Windows has less holes (as there's, oh, ten or twenty years of hard evidence to the contrary), just that less holes in Windows get patched. The articles I linked to above take care of this point quite nicely.
>Not as much software readily available
True. Whatever will we do without all that malware? Just kidding, I know what you mean, but aside from a few niche interests, most Windows software has a Mac equivalent, usually of higher quality. There are often a glut of Windows apps that all do the same thing, and two or three Mac apps that do it in a more readily understandable (read: usable) way.
>Replacement hardware more expensive (DVD burner $300 on a Mac vs. $35 for Windows PC)
That one IS true (though I haven't checked your price quotes, which I suspect are suspect). I wish Nvidia and AMD would stop making separate Mac and PC versions of their damn video cards already.
>Harder to learn how to use software
Different for everyone of course, but seriously? Harder than what, a toaster?
>Office 2008 isn’t all it’s cracked up to be on the Mac.
Haven't used it myself, but I've heard pretty bad things about it as well. Guess who makes Microsoft Office 2008 for Macs. I'll give you a sec for that.
>The @ key is in a different place.
LOOK AT A KEYBOARD. Any keyboard. Heck, go Google Image Search some Mac keyboards. English ones. Tell me the @ key is not the same key as on any other keyboard. Or just stop making stuff up, it'd be faster.
>There’s no hash key (why the hell not?)
The # symbol, I'm assuming? The one I just pressed Shift-3 in order to add to my post? Okay, bud.
>I have to reformat my iPod.
...in order to use it with Windows, if it was previously Mac-formatted, because Windows basically doesn't support any file system not used by Windows (big surprise). If your iPod is Windows-formatted (FAT32, in other words), Windows and OS X can both use it just fine.
>I can’t find any decent personal finance software. I’m sticking with what I’ve got on the PC.
Okay. I don't know what your needs are, so yeah, whatever works for ya.
>Forget about gaming
Mostly true, and in fact partially Apple's fault for not especially caring about games and pushing other interests ahead of it. However, you can always just boot into Windows for the odd game or two, and use a real operating system for everything else.
And y'know what, I'm not a Mac fanboy. I'm a good technology fanboy. I'd ditch OS X in a split second and sing the praises of Linux from Y!A's rooftops if Linux developers knew what the hell they were doing (their idea of a "graphical user interface" is more or less on the level of sticking a button on the main window for each command-line flag). So far, at this point in the computer industry's lifetime, Apple happens to be the company that gets the most stuff right and actually knows what it's doing. It wasn't always that way (the mid-90s are a good example of when Apple actually did suck, and Microsoft is just entering that stagnant phase now), and I'm sure it won't always be that way. C'est la vie.