We saw quite a few iPhone-toting folks at GLS, and also visited an AT&T store where we got to play with them for a while.
Yes, the UI is amazing. It's beautiful. It's seductive. And no, I still don't want one.
Biggest reason why not? I have semi-long fingernails (not outrageous, but feminine). And they make it nearly impossible for me to hit the keys on the iPhone's screen-based keyboard. It was incredibly frustrating trying to type in URLs or addresses. I don't have that problem with the keyboard on my Blackjack, nor is it an issue on a stylus-based interface. But the iPhone is really tough for me to enter information onto. That's bad.
My hope is that future models will include a styus option, or something that makes it easier for me to do text entry. 3G data would be nice, too. And the ability to send photos directly to Flickr. So, I can wait.
I saw this same thing mentioned on another blog -- that people with longer fingernails (particularly women with nails done) are having some trouble with the touch screen. Interesting.