A design patent application for this unannounced device was filed in the US by Sony Computer Entertainment. The document is light on details, but calls the device a “hand held game controller”.
It seems like this controller is being developed in the USA since all of the inventors are from southern California. More specifically, one of them works at Sony’s Electronics Design center in Los Angeles.
What could this be for? The way it’s designed to be held doesn’t look optimized for motion controlled sword swinging. Perhaps, it’s a quiz style controller for Sony’s Buzz series.