If you want to score extremely rare Shiny Legendary Pokémon Dialga, Palkia, and Giratina before Pokémon X & Y arrives on October 12th, you should take your copy of Black & White or Black & White 2 to GameStop starting August 19th.
Take your game and your 3DS or DS and grab each Shiny Legendary on the dates below. While you're there, I'm assuming GameStop would love it if you preordered Pokémon X & Y. Here are days you can pick up Dialga, Palki, and Giratina:
- Shiny Dialga - Monday August 19th, 2013 - Sunday September 8th, 2013
- Shiny Palkia - Monday September 9th, 2013 - Sunday September 29th, 2013
- Shiny Giratina - Monday September 30th, 2013 - Sunday October 20th, 2013
There's no word on how these Pokémon will transfer to X & Y (even though the developers are planning on a solution), but fans who still have their B & W copies can grab these once-in-a-lifetime catches while they're available.