I have this whole impression from a conversation I had with my father. He is the Regional Account manager for the 3rd largest pharmaceuticals company in the world, and to call him a "businesss user" of anything would almost be an understatement.
When I first came home with the iPhone, I came to his office to show him because he had only briefly seen it in the paper. I showed him the Calendar, and he said it was "Alright". I tried showing him YouTube, but it wouldn't load, and he said "I don't care about YouTube" in almost an inpatient voice. Next I showed him the iPod, and he was impressed. However when I turned it to display the Cover Flow, he claimed "Why would anyone care about the pictures?".
Lastly, he requested to see the E-mail, what he was looking forward to. He liked the way it was easy to read and simplistic, and asked me to call one in for him. However after reading these forums further, I had to break to him the iPhone "Isn't available to corporate users yet".
I guess the previous conversation supports the wide use of the iPod theory, but limits the argument the iPhone has a large businesss audience.