I just successfully synced pretty much my entire iTunes library to N900 via Salling Media Sync for Mac (I don't have significant DRMed music). Just plugged in the USB cable that came with the N900, selected mass-media transfer (or something like that) from the N900 popup that came up and clicked Sync in Salling Media Sync. No drivers needed or anything, it all just worked once Salling Media Sync was installed (click and play really, that too).

The N900 beautifully shows all the album covers and works well all around. It has this small, cool equalizer in the bottom right corner when music is playing.