This so far seems to be the one complaint I have...and I seem to be having different results than everyone else. I got my 8700 today and gave it a full charge before starting to use it, and within 5-6 hours with light e-mail/internet usage and almost no phone calls I was already down to 60-70%.
This is no where near the battery life of my 7290 which could go for 2-3 days on a single charge with moderate-heavy use. I will try again over the next few days and I really hope it gets better. Don't want to have to lower the screen brightness below 50%.
Cingular, 8800, OS v18.104.22.168
PIN # 23F51D67