Via http://mynintendonews.com/2013/10/0...ntly-in-development-possibly-pikachu-related/
Tsunekazu Ishihara, the president of the Pokémon Company, will apparently showcase an unprecedented Pokemon game which apparently begun development this summer. The game is said to change Pikachu, and Ishihara is ultimately worried that this change will affect Pikachu’s popularity. Japanese fans have already begun speculating that the change may be Mega Pikachu. Speculation is also rife that the game in question will be compatible with Pokemon X & Y, and Pikachu’s change could be carried over to these games.