Some random thoughts about the device now that I've had a day to play with mine.
The battery life for heavy Internet/app usage sucks. I haven't been able to leave it alone enough to judge otherwise. As it stands I'll definitely be carrying the charging stuff. Although it does last quite a bit longer than a notebook doing the same stuff.
The Internet everywhere is awesome. And with the iPhone it's been pretty much the same Internet as that on my macbook pro.
The applications are the killer feature. The iPhone isn't so much a phone as a handheld computer. The iPhone SDK definitely brings desktop computing and applications to a mobile device.
The keyboard is much easier to use than I expected. Pretty much instantly I'm typing accurate emough for the auto correct to get most erprs and at a very comfortable pace.
I may follow this up with some application reviews in the near future. However I'll say that NetNewsWire and Twitterific are both excellent. Oh, and my 2-year old loves Bubbles.
UPDATE: The batter life doesn't suck as much as I found at first. Spending hours using it non-stop and downloading apps and other such things tends to cloud the picture. I've since been able to use the phone normally for 16+ hours doing various things and still not have the battery completely drained.