Join Date:Joined: Aug 2012
Now, when you say "power on," are referring to the screen that is off while the phone is sleeping, or do you mean completely off?
AOSP roms do have the option to turn on the fly screen when you plug it in. Also, as of the new firmware release from HTC that came with Sense 5.0, or phones now turn the screen on when you plug in the charger (at least mine does...I never asked around to confirm this). But in both conditions, the device is powered on, but sleeping.