last night i was calibrating my battery on my new c2d mbp, and to try to speed the process along, I cranked my brightness to max, played a dvd in the background with the audio most of the way up, while streaming a 720p quicktime trailer from the apple site, all while using the migration assistant to move files of my old powerbook, with the performance settings turned to max. It still took over 3 and a half hours to drain completely, and as an interesting side note, in activity monitor neither core ever got above 50% or so.