Apple released iTunes 4.1 today, and now it is also available for Windows XP and 2000. This looks like a winner already being the first free AAC encoder and player for Windows. Interestingly, it does not support or playback Windows Media Audio (.wma) – a format that Microsoft is pushing so hard.
As for the Apple music store, it is still unavailable outside of the U.S. However, Canada just got the first download music store a few days ago: PureTracks.com. Unfortunately, they only support Windows (and their files are in .wma only).