The iPhone is the PS3 of Cell Phones
I think Apple is making many of the same mistakes that Sony made with the PS3.
Price: Sony made the mistake thinking people would pay $600 for a game console with no games. People don't have that much disposable income and they aren't going to drop $600 for their 8 year old to play games. Esepcially not when there is a $250 alternative from Nintendo.
Apple's iPhone costs $499 and $599, just like the PS3. When Amazon.com sells cell phone plans with the cell phone sold at negative $100, that's right they pay you, then the iPhone just looks absurd. Ok, so those phones are competitors to the iPhone, the smart phones are. Fine, but you can't get a Blackberry with internet connection, email, and music playing capability all for less than $200 with service plan. Similar prices are available for Treos and other Windows based smart phones.
Lock in: Even though you just want a gaming system Sony makes you commit to buying a Blu-Ray player which is embedded in the price.
Ok, so this is a stretch but Apple makes you commit to using Cingular. You can't buy the phone without a Cingular plan and many people can't receive Cingular service, have a large network of friends on another service, or appreciate a larger network of coverage provided by other services.
Developers: Sony's PS3 is known to be very difficult to program for because it has a very unique 8 core, asymmetric processor design that very few are trained to take advantage and their platform is also more expensive than competitors.
Steve Jobs has announced that third party developers will be locked out of the iPhone. I think this is suicicde. Consider Palm who for a long time had inferior hardware and a limited operating system yet thrived on the thousands of third party apps which created a strong culture and loyalty to the Palm OS.
I'm not saying the iPhone will "fail", but with those three aspects there is no way the iPhone will have the ubiquity of the iPod. The only people I know who would spend $600 on a phone are business people and considering the Blackberry integrates with corproate email while the iPhone does not (no third party developers) why would business people buy this?