This is the same thing Tommy Lee did on the Wii a while ago. This was dredged up right before the 3DS was unvailed as a possible way that Nintendo could of been doing the glasses free 3D. It was actually used in a Japanese DSi game (Rittai Kakushi e Attakoreda) where you serched for items by moving the DSi around the and camera appromiated the movement and moved the sceen.
http://www.youtube.com/watch?v=SWAg1s7xfz0 (Demo of the game)
And looking at the article they are even using the same target set up as Tommy Lee. I doubt this can be used as a "secret" weapon when it has been used already in other game(s).
Plus Sony seems to like using techonologies that push the sales of it other items. (3D TVs, new Super HD TVs, etc) So I really don't see this fitting into Sony's philospy.
