I love my iPhone so far, no problems with battery life- a good days use including a couple of hours of mp3 playback drops the battery by about a third. Oh and a good ten minutes of swinging iSaber around 
I've had two bits of odd behaviour- once Safari crashed, and the phone went back to the Apple power-on logo for about 5 minutes, then eventually rebooted.
Today I let an album play to the end, heard a click, and then it wouldn't play any more mp3s until I rebooted it.
A few minor bugs but nothing to really hurt the experience of such a great device.

I've had two bits of odd behaviour- once Safari crashed, and the phone went back to the Apple power-on logo for about 5 minutes, then eventually rebooted.
Today I let an album play to the end, heard a click, and then it wouldn't play any more mp3s until I rebooted it.
A few minor bugs but nothing to really hurt the experience of such a great device.