I agree. Apple has been violating their own human interface guidelines for some time- and iTunes 7.0 this just makes it worse.
Pretty soon my desktop will look just like dashboard- every app, like widgets, will have their own "skin." (I don't disapprove of "skinning" for widgets, but I certainly do for applications.)
Lets see... we have plastic, metal, aqua, iTunes 7.0, whatever they use in the pro apps, and of course Apple's Java doesn't fully support Aqua (a third party had to produce a L&F that adds much of the support that is missing.)
Keep this up, Apple, and I'll be using Gnome on Fedora Core.