4 Color Rebellion managed to get to the bottom of a not so mysterious link found on Nintendo.co.jp. It turns out Nintendo has created a custom DS console to be used by the Shigureden theme park in Kyoto "to operate and promote their 'Ogura Hundred Poems By Famed 100 Poets' exhibit."
From 4cr: "Nintendo cooperated on a interactive exhibition in which the floor contains illuminated pictures. You can walk around with a special NDS without any buttons, using only the touch screen to control the NDS. The NDS is used to give information about what you see on the floor and gives you an interactive tour through the exhibition."
This might have knocked two Nintendo unknowns off the list: the mysterious Floor Vision and Yamauchi-san's classical poetry interest (though not quite an animated movie).
[Via DS Fanboy]