iPod. Mac mini. MacBook Pro. OS X. These are Apple products that I have acquired in the last several years and that cause me much love, because for the most part, they just work. So what do I think about the iPhone?
Simple. I think it's going to be a boutique phone/media player for folks with money to burn and who want convergence between their phone, media players, and PDA. It's sleek and has a great-looking UI -- an Apple standard -- but the price tag keeps it from being a casual purchase.
I don't forsee it making inroads into the lucrative corporate messaging environment, though, because it doesn't offer any sort of synchronization support for the full Exchange experience. POP3 and IMAP don't cut it here. There's a reason RIM offers the BES option for BlackBerry devices, because individual cradle synch doesn't cut it. Businesses are demanding and using over-the-air sync with full support for all features of the messaging environment -- contacts, calendars, messaging, documents.
Now, I'm pretty certain the iPhone is going to hurt Windows Mobile in the consumer market...but its lack of support for Exchange or even Notes and Groupwise will keep it out of most enterprises.
BTW, note to Apple: I'd love to be proven wrong about this. You're more than welcome to send me a review unit, once they're available (FCC licensing is still pending according to the note at the bottom of Apple's website today), and I'll happily take it through its paces.