I believe this all falls under the old saying "A Jack of all trades and a Master of none".
Apple is known for doing one thing, and doing it well. While iPod has evolved from just music, it now also includes other forms of media for watching and viewing as well. However, meshing an iPod into a Smartphone is going to stretch iPod past what it can do well.
As I said before, I would gladly carry an iPhone and an iPod, but I won't pay for a hybrid since I believe functionally it couldn't serve its purpose as well as each by itself.
Ummm...Apple makes computers, remember? Since when did Apple become just an iPod company? I'm sick of hearing that Apple's philosophy is to makes devices that just do one thing and do it well. No, that's not their philosophy and never has been!!!! A better description of Apple's philosophy is that they make devices that "just work".
The phone thing is new to Apple, but they have extensive minituarization experience with the iPod, and they have PDA experience with the Newton. So I'm actually optimistic that Apple will be able to combine them (along with a phone) and create a device that "just works".