I have noticed the same thing with my Nikon D700. When outside in the shade or indoors with the screen off you can see that the inside (under surface)of the LCD screen glass has a generalized haziness (milky) and some streaking as if it has been 'wiped' in some areas. It doesn't affect camera function or screen appearance when in use. I emailed Nikon support the following:
"For several months I've noticed that the inside of my LCD screen has a "haziness" on the inside surface which is somewhat distracting in sunlight. I've notice on the web that other Nikon owners have had a similar problem. My camera is no longer under warranty. Do you repair this problem at no charge to us owners since it seems to be a problem when the camera was assembled? If you don't repair for free, how much would it cost to have the LCD haziness corrected? Loyal Nikon owner."
Below is their response:
"Unfortunately, Nikon products only have a limited One Year Warranty. We can not comment on third party web sites as they are not affiliated with Nikon USA. We can not provide you an exact estimate of repair cost, but what we can do is give you a "ballpark" figure where we give you the Highest and Lowest of what the prices could be.
The Lowest Price would be $76.00. The Highest Price it could be is $304.00."
I think I will try and call them to see if they will stand by there product and fix the issue at now cost to the customer. I will post their response.