2ch and various Japanese Pokémon blogs have posted an image from a Lawson pre-order chart which suggests that a new Pokémon Scramble game will be released soon for the Nintendo 3DS. Lawson will apparently begin allowing pre-orders for Super Pokémon Scramble (スーパーポケモンスクランブル) starting June 15th, 2011, so a release date would probably be sometime in the summer. The next issue of CoroCoro is due for release next week and it's supposed to be announcing a new Pokémon game.
The official Japanese Pokémon website has updated to post information about the game and to confirm that it will be released on July 28th, 2011 for 4800yen.