Funny you asked this question. I've long (LONG) been calling for a handheld Palm-like computer, just enough for me to schedule iCal appointments on. I know it sounds silly, but I just wanted to be able to use an Apple-designed portable scheduler that would sync with my Powerbook seamlessly. When iPhone came out, everything about it was exactly what I wanted, EXCEPT the fact that it includes a phone! I don't need a phone! My little tiny cheapo LG is perfect for my needs. But I do want a handheld computer.
I suspect the next iteration of the iPod with multitouch will be sufficient for my purposes, but I have no need for a do-everything phone. To me, a phone is a phone, and a computer is a computer. I am unconvinced that they should be merged.
Thankfully, however, I probably am in the minority here. Apple can make its money on iPhone, build some revenue, and then give me my NewNewton (or whatever they call it) when they have some money to blow.