I got a 4s about two weeks ago now (around Oct.26) and I have to admit that I have not noticed battery issues. I keep cellular data off unless I need it, and I keep wifi on when at home. I turned off all location services and I disabled push notifications for apps that I don't use (including e-mail). I use notification centre for about 5-6 apps. I keep GPS enabled for maps and that is about it. I try to remember to clear the multitasking list a few times per day.
All in all, with 3 hours and 41 minutes of use and a total on-time of 26 hours I am still at 49%. This works out to about 1.96% in battery drain per hour. I estimate that at this rate of battery drain, I should get roughly 7.5 hours of use and 51 hours of on-time (if I let if drain completely). To me, this seems within Apple specs.
If I leave my phone on overnight but turn off wifi, I lose about 3% over 8 hours; or 0.38% per hour in standby (well over 200 hours of standby if extrapolated). I am in the habit (now) of turning my phone off at night and it is generally only on about 10 hours a day. I last charged my phone a few days ago.
My phone was manufactured between Oct.10-16, 2011.