While waiting for “The Social Network” to get rolling, David Fincher’s been keeping busy going back to his old trade: directing TV ads. This spot for Nike Pro Combat features Vikings running back Adrian Peterson as a half-man/half-pigskin gladiator in a snowy, black and white clash of man-flesh. Produced by Anonymous Content for the Wieden + Kennedy Agency, this minute and a half clip might not be enough to tide you over, but at least it’s something. Don’t say we never gave you anything.