Some hard numbers:
I use pershoot's UV/OC kernel, keep wifi on all the time, and use softlocker to make sure my gtab *never* deep sleeps. This is on Vegantab-ginger.
I installed batterymonitor widget, and am collecting data.
My "screen off, but wifi on/not really asleep" power drain is 125mA
Given the 3650mAH rating of the battery, that gives me 29.2 hours total standby time in this state.
Working backwards, that's a drain of just under 3% per hour.
Given I am only awake 16 hours of the day, I have nearly half a battery to play on, or about 5-6 hours or so of full out battery, to use over 16 hours.
I'll keep collecting data and see if I can get even firmer numbers.
The widget is awesome, and free
https://market.android.com/details?id=ccc71.bmw
Make sure you go into settings and set the battery capacity to the rated 3650mAh to get accurate numbers/estimates.