you obviously know nothing about audio formats. Without drm, anything that supports AAC can play the song, and if not it's one click away from being MP3. The reason apple uses aac is because it's much higher quality. It's not that it can only by played on iPods, it's that only iPods support a good format, other playesr can if they want (EX: the zune plays aac INCLUDING from the store now that drm went away.)
Until you can plug in a competing MP3 player into iTunes and it syncs with no problems, there is still that exclusivity that Apple employs. You can also plug almost any non-iPod mp3 player into anything not named iTunes and it will sync in most cases. Is that the best policy to exclude any other mp3 player from working on iTunes? Probably. The music industry still believes that suscription is the way to go....idiots.