Evidence that shake, pinch, spread and multi-touch are non-obvious UI features that average folks would not discover quickly on their own and likely need help understanding? Please. At the very least, they'd need a short video clip or a getting started guide to explain these features. They're cool and valuable, but not intuitive.

I'm a relatively smart guy, and the first time I picked up a new iPod shuffle (with the controls on the headphones) it took me quite a while to figure out that: 1) The area between the volume up/down buttons was a separate button 2) How to use that center button.

Apple has gotten very good at forcing people to learn new, unfamiliar interfaces. To say that these interfaces are better is a matter of opinion, and to say they're easier than a mouse puck on the desk with a corresponding screen cursor and a "start" menu or icons on a dock is laughable.