It's through an ad for some Pokémon Movie 15 marchandise (a set a DS stylus) that we learn about the legendary Pokémon that will feature in the upcoming Pokémon 15 Movie/ Unsurprisingly, the Pokémon are: Kyurem, Cobalion, Terrakion, Virizion. And along a Pikachu stylus, there's also another one for a mysterious Pokémon, yet to be revealed (no doubt it will be one of the legendary that are yet to be revealed in the games).

Source: Serebii.net frontpage. Sorry I could find a higher-resolution picture.