Back in 2006 I saw this demo video from Jeff Han https://www.youtube.com/watch?v=UcKqyn-gUbY so when the iPhone came out I really wasn't surprised by the multi-touch part. And, as others have pointed out, scroll inertia wasn't a new concept - I also remember a Flash website (or demo) from yugop (Yugo Nakamura) or Tokyo Flash (I really don't remember whom) that had it in the interface, all very fluid.

Was the iPhone revolutionary? Absolutely!

But, imho, it was built on evolutionary advancements.