This Mini Player view is notable because iTunes is the only iApp that has such a state. Ostensibly this is because you may need quick access to your music controls when in other apps. But I think some other apps could use a mini state. Specifically, Apple’s Mail.
My initial reaction is that it’s more of an argument that Apple
should allow Dashboard widgets to live in the regular window
layers. There are some widget-sized status windows that’d be convenient to keep visible all the time.