Like others here, I'm not a big cell phone user. But, I'm very interested in what is effectively a pocket computer. Full web browser, sync to calendar / address book, etc. The iPod functionality is nice, but I can live without that -- my Nano fits quite well in my bag. The video capabilities are also interesting, but I don't see myself using that a lot.
I think the iPhone is especially compelling for Mac users, for the excellent synchronization with iPhoto, iCal, Address Book, iTunes, etc. (iPod does this today, but with no input capability it's not too useful).
The main things holding me back from buying one:
- Two year commitment to Cingular/AT&T without any subsidy of the phone cost.
- Unknown Call / Data plan requirements. Will I be able to use my current $40/month plan? I doubt it. Probably $60-80 minimal cost.
- No 3rd party apps / development. -- As a relatively new Cocoa programmer, I was excited about being able to write my own apps for the iPhone. It would have been a no-brainer with this. But, without any 3rd party apps your at Apple's mercy. Big drawback.
- The cost is an issue, but relatively minor for me. I'm willing to pay a premium for something that meets my needs well. The MacBook Pro fits that category, and I did buy one. If I was happy with the iPhone, I would pony up the cash. As it is now, I'll wait for actual user reports before buying. I may buy the first revision after the intiial release. Or, I may not buy one.