I would consider mine to be normal. I put 8.0.2 on Friday and over the weekend and today everything is fine. This morning the Battery Usage is telling me it's been on standby for 2 hours 31 minutes and 1 hours 15 minutes of usage and I'm at 94%.
My iPhone 5 is draining quite a bit faster on iOS 8.02. It worked much better under iOS 7.
Sat at airport this morning and made three calls at 100%. Within 15 minutes, down to 92%.
On airplane for 4 hours with AP mode on and it dropped to 60%??????
Might also want to check the actual battery usage by app. That feature comes in handy if you want to track which apps chew through the battery life.
In one 24-hour period, I saw that 96% of the battery usage occurred with one gaming app. When running that app, my battery life was probably around 3 hours. Without running that app, yesterday I saw more than 3 hours of usage, and 9 hours total, with 55% battery life left.
If anything, the battery usage on standby with iOS 8 seems to have gone down a lot, and I suspect that has to do with wi-fi calling. I'll do a more direct comparison when I have time.
Like Yun0 said... there is a battery replacement program running. Mine was eligible and before the program started, I was facing serious issues (since iOS 7 beta 1 coincidentally) that my battery would arbitrarily shut off. I thought okay, software issue, waited and waited for "battery issues" to resolve. When the program started, I was like, about time, Crapple. Thanks for making me insane for a year... got replaced and waiting to go collect from the service centre. You should check too.