I ran a little test yesterday. Fairly moderate use at work (Texting quite a bit using Google Voice, email, browsing), and two hours listening to music at the gym. I went off charger at 6:30am, and when I went to bed at 11:30 was at 60%. Woke up at about 57% this morning.
24 hours off the charger with what I would consider more than average use, and a bit over 40% of the battery drained is fairly amazing to me.
I take back every nasty thing I ever said about iOS and the iPhone. I'm glad I switched.