Apple has released some new info about the iPhone today - Battery life is significantly better than Apple estimated back in January!
The improvements are pretty impressive. Talk time is up from 5 hours to 8 hours, Internet usage up from 5 hours to 6 hours, video playback up from 5 hours to 7 hours and audio playback up from an estimated 16 hours to 24 hours. Bear in mind that this data will vary considerably depending on real-world usage, but it's still impressive.
Sounds like the Apple boffins either managed to cram a bigger battery into the phone or squeezed better efficiency out of the components.
One thing that I'm still waiting to find out - is the battery user-replaceable? Oh, and how usable is the virtual keyboard? :-)