Well, I spent what little time on Saturday I had free reading iPhone reviews, watching the 'first unboxing' videos, usage videos, screenshot galleries, etc. Darren found a nice initial (but in-depth) review of the wee beastie (I want one!).
The end result from pretty much everything I've read is that it's gorgeous and amazingly user friendly (JK has a nice writeup on the little details that make Apple the leader in UI. It's not the major things, it's the little bits....) and gorgeous to look at and use. They keyboard gets some getting used to, and EDGE for data transfer sucks slightly more than other options. Definitely sounds like the pros outweighs the cons by a long shot though.
Time will tell if future gens of the iPhone will make it more useful across a broad spectrum. Business usage is lacking and the absence off GPS, Java, and third-party software kinda stinks. I read an article on this at www.iphailure.com
It brought up some decent points you won't see in a lot of big name newspapers that seem to LOVE Apple.