Looks like another issue has come up about the Surface Pro, this time having to deal with a "brightness bug." The problem has to do with the device randomly dims and brightens even when auto brightness and dimming is disabled. Microsoft is aware of this issue and is currently investigating.
"The surface pro randomly brightens and dims even when auto brightness and dimming is completely shut off. I contacted Microsoft chat support and they said they are aware of the issue but its taking longer than expected. I just wanted to post here to create more visibility and awareness of this annoying bug. I hope it gets fixed soon. Its most noticeable when an app launches or while beginning to watch a video. From what I've heard it happens with RT too," a Surface owner stated in Microsoft's official support community.
Microsoft's response? "Sorry for the delay. We are aware that this issue occurred on the Surface with Windows RT and is occurring for some users with the Surface Pro. We are investigating what is causing the issue."
Apparently this issue occurs on the Surface RT as well. One Surface owner noted that the bug appeared when the device was running on battery, but did not occur when it was plugged in. Microsoft is working on fixing this issue and perhaps we will see an update during the next round of updates in March 2013.