I have now used the iPhone for a few days, and while it isn't perfect by any stretch, it is quite a capable mobile system. The phone works as advertised, and the so-called "hype" wasn't a set of over-promises, but rather an honest assessment of capability. As a phone, it has the most intuitive interface I have used. For example, when starting a call while having a BlueTooth headset active, the phone pops up a dialog that allows you to change the active audio device. The way that the phone displays options for incoming calls, call waiting, and other situations is quite clear. There do seem to me to be times when the call and hang-up buttons change places in different modes.
I am finding that the keyboard is becoming easier to use, and I think I'm already faster than I was on the Treo, primarily because the system corrects mistypes and the virtual keys are actually larger than the keys on the Treo as the system guesses the words. The maps application is very useful and amazing in its appearance and function. I'm about to take a trip where that will come in very handy. I'll report on that later.
Today, I had an issue recording a new voicemail outgoing message. The iPhone is different from other phones in that the message gets recorded onto the phone, then transmitted up to the voicemail system. The advantage is obvious: the sound quality is of a local recording, not a message recorded over the cellular network.
However, today I couldn't update it after my lovely bride suggested I could make it sound better. So, I called AT&T. They put me on hold for quite a while, and when they answered again it wasn't AT&T... it was Apple! The tech suggested I reset the iPhone (touch and hold home, then hold down the power switch until the gray apple appears). After I did that, the iPhone worked just fine. And interestingly, a stubborn SMS message finally decided to be sent, too.
So, clearly, it's not quite perfect, and I'm sure that others will find reasons to complain. However, its combination of size, weight, human interface, capabilities, and upgradability put it head and shoulders above any other mobile device available today...
...from the perspective of this pragmatic technologist, at least.