Supposedly it's hardwired, you can't power the camera without powering the LED. I wrote a security app that grabs from the iSight every few seconds, and got tired of the light flashing on and off all the time, so I just covered it with a little black sticker.

Would you want that as a feature? Keep camera on but turn off the light? Hmm...

Sounds like being able to do that could be a huge security/privacy concern...