Forget the hype for now, there are people who are going to buy this thing @ launch FOR SURE. The bottom line is user opinion, if this thing gets bad reviews/ bugs found right away, Apple will have a problem. Everyone is interested in it, which IS EXPECTED since most of us own Ipods AND phones, who wouldn't be interested in a 2-for1 device?
I agree. When I first saw the device my first thought was that the whole one button thing would be off-putting and might relegate it to a small niche, but as best we can tell from the various surveys we've seen that doesn't seem a major factor.
Interesting to try to think of bad user experiences that could kill the iPhone. Here are just a few that come to mind:
1) Most people find they really can't get by without physical number keys and/or the touch-based UI (incl. the QWERTY) turns out to be tricky.
2) In reality it's not half as pretty as it looks in the pictures.
3) When they actually hold it people think it's too big.
4) It's buggy, unstable, perhaps dropping calls or having other functions that just don't work as expected or it crashes.
5) It breaks.
6) It has poor voice quality.
7) It has bad battery life.
8) It has poor music quality.
9) The screen scratches easily.
10) It's slippery.
Etc, etc. Mostly stuff that's true of any device like this. At this point (as I was saying above) things seem to be going pretty well for Apple. They've designed a device that (on paper at least) people seem to like and say they want to buy. It's perhaps a little trite to say all they need to do now is deliver, but certainly they do need to do that, and that's no small task. Apple of course have lots of expertise in designing electronic devices and OSs that go on them, but on the other hand this is a first gen device and their first phone. I suspect they will get it more-or-less right, but given the level of hype and anticipation, the capacity for (perceived) failure really is quite huge.