Tsunekazu Ishihara (the president of the Pokémon Company) will be on Japanese Television on 28 October. The run-through of the interview mentions and discusses the extraordinary game development that started this summer. The game is said to change Pikachu, and Ishihara is concerned about how the change will affect Pikachu’s popularity. More informationwill however be revealed in the interview.
Japanese fans are speculating that the change may be a Mega Pikachu. This is certainly very possibil, even though Mega Evolution is really reserved for fully evolved Pokémon. It is also possible that it will be compatible with XY, and thus Pikachu’s change could be carried over to these games.