I've been noticing this issue too. i.e. much greater battery drain after JB upgrade. I was getting great standby time on ICS (and also DIDN'T have a whole host of other little issues that have been plaguing me since the 'upgrade.') If I could easily get my phone back to ICS, I would. It worked great then and I wasn't obsessed with the battery life all the time
I realized that although I have turned off google now, I hadn't turned off the location history. This is THE major battery drainer because Google is using juice to constantly monitor where you are so it can readily provide you with local suggestions. This is pointless, however, as Google can ping your gps when needed just by turning this option completely off. I'm hoping this reduces the standby battery drain. Today I averaged about 7.2% / hour and I've turned off most obvious battery drainers.