I am on a Droid X with 100% charged battery.
Playing Dragon Warrior VII it only lasts a little over 2 hours (I'll get the exact time another day)
However:
My phone is overclocked at 1300 MHz
It is also using HDMI out to my TV
It is also using bluetooth for my Wiimote and nunchuck.
So I guess those three things can make the battery deplete faster but is anyone else getting the same results as me?