Apple is going to get rich off of iTunes on Windows. Let me just start with that.
I downloaded iTunes for Windows. I've used it on my Mac for awhile and it's basically identical on the PC to its Mac incarnation. And it makes sampling of music, purchasing, and downloading so seamless at such a reasonable price that excuse for pirating music is gone. This makes it so easy and convenient that people will be buying music in vast numbers. It's a win-win situation that I think will eventually become Apple's main business. In time I can see this being expanded into DVD videos, software, and beyond.
Now, before the email starts pouring in, yes, I've tried some of the other alternatives already. On Windows, I've been using BuyMusic.com. It's nowhere near as seamless an experience. The integration between the player and the store makes a big difference that favors iTune. One click purchase and download is a big deal.
But BuyMusic has some advantages over iTunes that need to be brought up. To do that, let me explain the difference between the "Windows people" vs. Apple.
When you buy a song from BuyMusic.com you download a .WMA file with digital rights management on (i.e. copy protection). From Windows Media Player, you can burn a CD with it, play it, or copy it to a portable MP3 device that supports Digital Rights Management (none of my portable MP3 players support DRM WMA's -- only standard .WMA files).
What that means is that Apple and Microsoft are actually closer together in the race for mass acceptance of their formats. Sure, .WMA has a lot more support than .m4p/AAC but what you're downloading from places like BuyMusic might as well be called .Whatever because as far as the average user is concerned, DRM protected .WMA files are a totally different format. They won't play on most portable MP3 players. You can't burn them to CD with most CD ROM burners right now.
So in essence, Apple and Microsoft are starting out at the same point. The question is who will be able to get wider industry support faster? Apple with .m4p/AAC or Microsoft with DRM WMAs? Apple has a leg up because of the iPod and iTunes includes a rather nice CD-ROM burner in it.
The bottom line is that Apple is in very good shape with iTunes. It works fantastically so far (better for me than it does on the Mac where I get weird copying problems and songs aborting early for no apparent reason -- <note to Mac fanatics: Yes, I'm sure I'm the only one who is running into that despite the posts on Dejanews and on Mac tech sites of people having the same problem>). It makes purchasing easy and tempting.
Today is a good day for Apple Computer.