>The glass on the D3, 3s and 4 are all tempered glass. Much >harder and more durable than the other Nikon bodies. It really >doesn't need a protector unless you are prone to really >beating up the back-side of your camera.
Well, Nikon has already approved and answered my question in the D4 Forum, and agrees with you. The Nikon answer:
"D3 & D4 have a very durable monitor that doesn't require a cover. If you feel more comfortable with some extra protection put a plastic film type protector on it."