YES!!!! I have had the same problem....it's terrible. I googled it and there is definitely a problem with the new software update causing battery issues. Apple has some suggestions to help it but it doesn't make much of a difference. I hate it! I was doing just fine with the other software.
I have heard at least some Apple Developers (I am in the Private $99 a Year IOS Apple Developer Program) who are constantly Flooding the Private Apple Developer Forums with Posts Complaining about IPhone 4S Battery Life, it got so bad that Apple Recently Closed the Forum that they were posting the messages to (which was supposed to be a Forum about IOS 5.1 Installation Issues only), and they also Locked all of the posts that were just going on and on about IPhone 4S Battery Life.
I would agree. Also I see now a lot of apps out and I have to go back in which uses data and battery. Sometimes I'm in the browser and it leaves without me pressing home key .
I hope that I am not going to have the same problems as you guys tomorrow when I get my brand new IPhone 4S delivered to me tomorrow afternoon. I already payed for it through BillMeLater.com, and this is somewhat of an Emergency Purchase for me since my current IPhone 4 is occasionally Over Heating.
I use a program called "Battery Boost Magic" and so far it is all it claims to be. I honestly do not remember if I got the free app or the 99 cent app. It is well worth the 99 cents.
Once a month you let your phone run down to 20 percent or less. Then Battery Boost Magic trickle charges it, tops it off, and then tops it off a second time. I was able to ride in on the train on 3G, surfing the web, all the way. Taking one or two calls, and when I got to Penn Station an hour from the station I started from, I had 98 percent power.
On a heavy day 10 hours, with a good amount of calls I can only drive it down to 59 percent. For me it is magic. Because without it, I was able to hit 76 percent on the way into work. I use my iphone to trouble shoot, in fire alarm panels. I set the phone to speaker phone and sometimes for an hour, myself and a coworker will trouble shoot circuits. On this particular day I did this for almost two hours, and only drove the battery down to 59 percent. It works for me.
It is unfortunate though, that now I have to purposely run it down by playing videos, once a month to give it a full cycle charge. Because even over night it will not run down to 20 percent. Ha-ha. And I have Wi-Fi running 24-7.