According to a Amazon listing of LEGO City Undercover, the Switch game box dimensions are 6.8 x 5.4 x 0.6 inches. This is exactly the same size as the game boxes for the Playstation 4 and standard Blu Ray movie cases.
Of course this doesn’t mean that the disks or cartridges inside them will take up even half the amount of space given. The Switch presentation takes place tonight at 11 p.m. ET.