I received my new Note late yesterday morning and had it charged by 1pm. It was in use most of the rest of the day until around 10pm when the battery finally gave up. Wifi was on as all the time. The battery warning came on very early, some two hours before the battery actually stopped, which is probably because it was new and there was no profile built for the battery yet. So that's 9 hours of fairly intensive use and this could improve after a few charge cycles.
PS just remembered I did have it connected via USB for a short while when installing KIES, not long, maybe 15 minutes.