Over at XDA people are reporting battery life settles down after 4 days or so average use?
Mine's no worse than any other recent smartphone I've owned - I've browsed the web loads today, been jumping in and out of forums on Tapatalk, Facebook and Twitter access, in and out of 3G areas while driving, connected to Bluetooth car kit for about 4 hours and made about 30 mins of BT connected calls. More calls while at home too.
In total, phone has been off charge for about 11 hours and I still have 32% left - thats pretty good imo considering its only on its 2nd charge.
Think it'll get better over the next few days as well - patience people
Oh and also - if you connect to the PC companion software you'll find there is a Firmware update now out to download (well there was on my sim free phone anyway).