See that would be a huge problem for me. I have 25 GB of music on my phone and I legitimately listen to all of it on shuffle. I travel a TON and I need my music, haha. I can't hear the same thing twice in a month or I go nuts. That being said I do make playlists for parties and stuff, so when I hear a good song for one of my list I love being able to modify my playlist right there on my phone and then know it will sync into iTunes when I plug it into my computer.
I have always wondered if Droid could find a way to make the phones iTunes compatible via some backdoor method. It would be sick if you could sync it with iTunes just like an iPhone.