I went from about 5-6 hours on a full charge (idle) and 3 hours (moderate use) to about 2.5 days (light use) and 1 day (moderate use). Not sure if the battery got "worn in" or the application updates from Nokia fixed something, but I can FINALLY use my phone with iphone battery extender.
Honestly, this was the best and worst phone I'd ever used til that point. Now I have SOME pride in the device.