Basically the iPod works a lot like the empeg does. Files are renamed and stashed away on the hard drive while all the real data the player uses is in a database. The main difference is that the empeg rebuilds the database, but with the iPod only iTunes can rebuild it. MSC allows people to store other files on the iPod, and also allows Apple to avoid having to write their own drivers for multiple platforms. Instead iTunes can just go out and look for the drive that is an iPod.