According to a latest patent uncovered by a NeoGAF user, it has been revealed that Sony has patented the Wii U style tech in 2009. You can check out the description of the said patent below.
The patent says: A portable electronic device comprises a display facing in a first direction, a video camera facing in a second direction substantially opposite to the first direction, a receiver operable to receive supplementary image data from a remote image source, the supplementary image data comprising an indication of where a supplementary image is positioned with respect to a reference image, and in which the portable electronic device is arranged in operation to display a captured image from the video camera on the display of the portable electronic device, and when the captured image comprises all or part of the reference image as displayed on a separate display, the portable electronic device is arranged in operation to display the supplementary image positioned with respect to the reference image, instead of the corresponding part of the captured image.
Application Number: EP20090252928
Publication Date: 08/24/2011
Filing Date: 12/31/2009
You can check out the images below.