The Kalos region is based off France, home to Paris, the 'City of Light." Lumiose City is a play on "Luminous City," or "City of Light."
The boxart of both X and Y(more noticeable on Y due to the dark background) depict rays of sunlight shining through clouds.
Xerneas's horns appear to be made of light.
I'm really starting to think that "Fairy" type will be called Light. Or at the least there's going to be a Light type. Thoughts? :) --- 3DS Friend Code: 2964-8909-6218 Official Modern Pit of the Kid Icarus: Uprising board!