A good section of Core77's (rare) Apple lead designer Jon Ive interview is about the danger of relying too much on technology to build technology. And the danger of not touching the materials you work with. [Core77]
...It is this sort of materials obsession and constant experimentation that led to a decision to use scratch-resistant aluminosilicate glass...
Oh come on, just admit that you used the Cowon S9/Zune HD/other device with gorilla glass and you thought 'wow this is pretty neat stuff we should use it for the iPhone 4.'
It has had nothing to do with 'material obsession and constant experimentation'.
I believe that you went to great lengths with the steel edge and all, but Gorilla Glass is pretty standard fare nowadays.