Ahhh, good catch rjeatkconley! I didn't even notice the wifi icon. And yeah, technically your phone will use more battery on both wifi and data. On GB, that drained battery big time. I am not sure how much on ICS because I have been in the habit of turning data off when on wifi.
I do know that GB used to drain my battery on 4G/3G mode but since ICS, I don't bother with 3G only anymore because I don't notice any difference in battery. So, maybe there is not much difference having both wifi and data on either.