A limited selection of music would seem well suited to Windows users - seems like the top 40 is all you would need for a bunch of lemmings who follow the pied piper of IT. Perhaps that was too harsh.
Somewhat related, is it me, or does the new iTunes for Windows commercial not make it perfectly clear that iTunes for Windows is out. It just says "Mac or PC" - the first time I saw that, I thought it was asking me "Mac or PC" not telling me "Mac *and* PC" - again, this could be due to me always jumping to the defensive against so many windows people who bash my Mac, but I thought the ad was a little short on a clear message.
P.S. Time magazine had an article comparing all the music pay sites and rated iTunes the best, hassle free - I think I saw this in the doctors office last week - it might have been an old article, but it made some good points about how iTunes makes it very simple to buy songs - not just the software, but the buying process.