Thanks everyone for your thoughts on this thread. I am very confident that screen brightness has not been modified by any of our software releases. In fact, this is a low level function that would require a flash of the operating system to change. By chance have any of you experiencing this issue flashed your OS?
The display itself is a high quality Samsung LCD screen, and from my research and personal experience these screens do not degrade; but it's not impossible. If you think you're having a hardware issue contact our support desk; we will need to see the unit to give a definitive analysis of the problem.
To make this conversation more open to other owners for feedback I'm moving it to the Owners Q&A forum.
Thanks!
Walter