Honestly usage depends a lot on how you use it, your brightness, notifications etc. When I browse over Wifi on the 4S, I lose about 10% every hour, so 1/3rd less than you, which is about what the iPhone 4 got on iOS4.
I think some of you are being a little too anal about this.
Turn off the battery percentage, and enjoy the phone. If you absolutely need to be on the phone for 8 hrs a day, get a battery extension. I'm in medicine and actually am one of those people who use my phone over the internet all day, and I still don't log more than 5-6 hrs of actual usage over a very long day. I can't imagine some office worker with a computer right on his desk using more hours, unless they're on Pandora all day, and in that case, plug it in.
Get to work! y'all playing too much.