I think that this is really what Apple should do:
-Make a new app that manages iOS devices and also lets you shop for iOS apps.
-Make iTunes work exactly like iBooks does on iOS devices, it's a place for content and also a store for that content.
-The iOS management app would let you sync iTunes content just like it lets you sync iPhoto content. It would also have all of the iTunes stores available within it, but to play music it takes you to iTunes.
This way Apple still gets to put all the parts of the iTunes store in front of everyone with an iPod or iOS device, but the actual music player gets separated out. Maybe the music/video player part of iTunes could just become part of QuicktimeX, or the other way around, iTunes becomes Quicktime X with library management.