If you want Plain Jane graphics, go to Android... or, even worse IMO, Windows mobile. Talk about ugly! Primary colors, square shapes.
One of the greatest strengths of Apple products and operating systems has been the intense attention to graphic detail. I can't believe a company as vast with talent would toss operating capabilities in favor of graphic design - no matter what. Quality in every aspect seems to be the Apple strength. I, for one, hope Apple "stays the course" in its use of creative graphics.
Suggestion: Perhaps a selection of skins for various apps might be appropriate - then everyone could either choose the one they like OR possibly create their own. Or, better yet, open skin design to developers in the App Store.