Is iOS 7 a throwback to OS X 10.0 "Cheetah"?
Take a look. 10.0 brought the rectangular dock, which Apple uses in iOS 7. There are transparent menu bars. You could even see through the menus at the top menu (File, Edit, etc.). We all know there are transparencies everywhere in iOS 7. And of course, 10.0 brought brand new interface element appearances but didn't actually change the interface too much, just like iOS 7.
I'm not trying to start anything in the comments, but just something interesting I noticed.