I know it's only the beta and was only released today so I don't know it there are any further plans related to the arc lamp, but if it's not already planned I would like to suggest being able to turn arc lamps off if they receive a redstone signal.
Well while this is (kinda) off topic, but I didn't want to create a whole new thread for it, may it also be noted that arc lamps have some placement/directional issues. I can't screenshot at the moment, but just incase Mic or Rad hasn't noticed yet...