First tests seem to indicate battery drainage is fair. A small test indicates that the device in unattended mode only takes about 3% battery life in 2 hours (100% -> 97%). The keypad lights have been blinking every 3 seconds during this time.
If I have something ready to test massively, I'll let you guys know.
Nice! Maybe this can be done too:
http://xdaforums.com/showthread.php?t=621846