No, he hasn't used it yet.
He did write an anti-moire filter for Final Cut Pro for the 5DII.
Here is a bit more:
"More megapixels for video causes these issues: Image size needs to be drastically reduced to get down to the 1920×1080 full HD video image, and to do that in the Canons has meant line skipping, information binning, which gives us moire and aliasing. Not nice. In fact, very ugly. I am not sure how bad the binning is on the D800 but that is a lot of information to throw away. The image is 1.6x larger than the 5Dmk2, so that worries me. I have noticed some image issues on the video below, but never judge image quality based upon a compressed web video. I need to see the original, or better still, shoot with the camera to form a proper opinion."