There have been issues with battery drain from the first release of Gingerbread, here's an excerpt from the Nexus S users in Mar 11.
As if some disagreements with Google Voice weren’t enough, the list of complaints against the Android 2.3.3 Gingerbread update for the Nexus One continues to grow. A significant number of users are reporting that the update to Gingerbread is leaving their Nexus One drained of battery life. While idle power consumption running Froyo amounted to about 2 percent on average, some are reporting that Gingerbread is registering power usage of 40 percent and above. One user claims his Nexus One ran through 40 percent of its battery over night sitting idle on his nightstand.
The issue seems to be related to how the phone and OS are handling idle services while the phone is sleeping with its screen off. While turning these services such as Wi-Fi on and off seemed to have no effect, setting Wi-Fi to never sleep actually conserved battery life versus setting Wi-Fi to sleep when the phone sleeps.
There is also a thread over at XDA regarding the problem - [Gingerbread] battery drain issues - info from samsung.
Android OS idle using between 50% - 75%
I think the story is that if you had battery problem before Gingerbread then they are solved. If you're battery was fine before GB then it's not good???
Edit: There is an app on Android Market called 'Battery Calibration'.
"Your battery stats maybe a little messed up if you often tinker with your Android device, flash ROMs, and other general shenanigans. It is probably because the batterystats.bin system file remains optimized for your previous states.
However, XDA-Devs have found a way to simplify the process even to clean up the battery stats. When your phone is fully charged, what you should to do is to install an app, named Battery Calibration."
Link to Android Market - Calibrate Battery