All right, don't have any hard #'s or %'s for you, but anecdotal evidence says the ultrasn0w update fixed the battery drain for me. I've been almost 2 full days on a 100% charge and I'm just now approaching 6% left with light browsing, mail, camera, texting, notifications, location, wifi, 3G, you name it. After this charge fully drains, I'll fully charge and will have some more accurate #'s but I am one happy JB iPhone owner 🙂.
Oh and pre-update, overnight (6-8 hrs) I would lose 15-20%, I am now only losing 3-5%.