[nemothekid]

I'm not sure that is entirely valid. Most smartphones before the iPhone were touch screen - resistive and needed a pen, like the Palm Treo, and the many Windows Mobile Phones before it, - but still touch screen.

Having a capacitive screen only seemed like the next logical step, and of course to do it well, you will need to the change the UX.

In any case I think its disingenuous to contribute the iPhone's success to the top-down touch screen when many of the game changing features were brought to light after the iPhone went to market, such as the Apple-Controlled App Store.

Lastly, there is no way the touch screen could have been considered top-down from Apple in 2007. The touch screen interface had already been iterated numerous times starting in 1987 with the Apple Newton.