The story about how Apple leveraged its design patents to win these trademarks is a fascinating study in rent-seeking at its finest. They used them as a bridge to "nontraditional trademarks."
What's really interesting is how the Patent examiner suggested changes to Apple's trademark applications so that they could get in under the wire. Sounds like a bit of corruption to me.
Apple has had nothing if not a gigantic first mover advantage over its competitors thanks to rapid and repeated innovation in product design, as well as great execution and saavy marketing. Add it all up and you get a company with a long-term market beating stock, propelled by net operating margins consistently over 20% and a weighted average cost of capital under 10%. Valuepro.net pegs the latter at about 8.6%. Apple long ago earned back its cost of capital on its iPod.
The idea that Apple's recently won trademarks are necessary for the company to earn its shareholders an above average return on capital (or equity) is plainly contradicted by the facts of the case. Too bad the Patent Office examiner doesn't have some economics in his toolkit.
Btw, Apple patented its transparent stairways in its stores, so don't think you can copy their cool design at home.