Something just occurred to me, which is great. Because iTunes for Windows will most likely be very popular, a nice side effect is that, because it requires QuickTime, Windows Media Player and related technology will take a hit in its growing dominance. Yeah! For the Windows folks who have yet to get QuickTime, iTunes is a nice "in".
That's important to me because I do a lot of QT development and it's really irritating seeing an inferior technology (and one not based on standards) start to take over.