Microsoft was stuck on making Windows Mobile a small PC.
RIM was poo pooing the touchscreen two years after the iPhone came out.
Google was aping the Blackberry with the Android and completely started over after the iPhone came out.
Nokia didn't have the OS or the platform to make a full fledge smart phone. But they were the most likely.
Don't get me wrong - the iPhone was ground breaking. It's the hundred little details that made it special.
But would someone else have done it? Yes. Is this relevant? No
But it would have been one phone among 50 they sold, the gestures would have been clunky, it would still have had a physical keyboard lurking somewhere, their salespeople wouldn’t have known how to sell it, and everyone else would look at the market crater and decided the idea would never sell.
The iPhone was always going to happen as soon as capacitive multitouch technology became feasible at the consumer level.
The LG Prada being a touch screen and therefore would have evolved into the iPhone is as unrealistic as thinking whatever the knock off touch screen phone that Sprint released in late 2007 was going to evolve into an iPhone.