Quick look at the specs of the Apple iPhone: High-resolution multi-touch touchscreen, Mac OS X built in, no dialing buttons, camera and music player built in, email, browser, Bluetooth, WiFi, cellular.
Quick reaction: This isn't a phone, it's what mobile computing was supposed to grow into. The phone is just a part of it, and in my opinion not the dominant part.
I don't think this kills RIM; a hard keyboard is better for dedicated e-mail hounds. But for entertainment-centric users, this looks like the device they've been wanting without even really knowing it.
I wonder how long the battery will last with Mac OS X in it.
More thoughts later. (Update: Now posted here.)