Not sure why people are complaining about the battery life so much. Should it be better than what it is? I think so. Does it suck regardless? Not at all. I consistently get 17-20 hours out of it with between 3-4 hours on screen time if I'm using wifi primarily, and around 13-15 hours on HSPA+ with the same usage. On screen usage is primarily Facebook/Twitter/Google+, a lot of texting, and web browsing. I don't play games or watch Youtube that often. Probably between 10-20 minutes of Youtube. That usage also includes 30-45 minutes of talk time. Now these numbers are consistent with the Galaxy S3, but I feel as if it should be better given how much more efficient the processor and screen are. So my guess would be that Android 4.2 is the culprit and we'll see some kind of update that may help in that regard.
For those of you getting different results, look over the differences. Do you watch a lot of video or play games? Do you spend any significant time in a bad signal area? Is your screen brightness past 20%? Are you taking a lot of pictures? If I did any of those things, my results would be much different, too. For me, this battery gets me through the whole day and then some.