--> I am yet to conclude my opinion about battery life of this phone.
I know I can't expect Symbian like battery backup in android but I had to charge my phone couple of times in first two day after just couple of calls and 3g internet usage. (Not even moderate usage.)
But since then I am sort of satisfied with the battery backup as I haven't charged my phone for last 2 days. (Used WiFi, Used GPRS, played games, used camera flash and still 13% is left.)
Because of these 2 contradictory incidents, I am yet to conclude my opinion on battery backup.
First, congrats for the purchase! Welcome to the world of Android.
Well, Android phones does something called "Calibration" of battery during the first few days. After that battery life is suppose to increase. That's why you faced the two contradictory results. But I am sure, from now on you will get better battery life.