This would work, if it didn't make things more difficult for less common tasks (many Linux distro's suffer this same problem, everything is great and productive when you are performing mainstream computing. However, cross the boundary slightly, and you'll find yourself in bash shell, which ruins all productivity benefits).

Sorry, but this isn't a good idea. iTunes actually wouldn't be half bad if they permitted addons, theming and official support for MTP/MSC. However, inconsistant UI's are a big no-no according to the lecturer who taught me GUI design, because users have to continue learning and cannot rely on elements existing where they expect them.

Just my 2cents though.