To promote the upcoming movies
Victini and the Light Hero - Reshiram / Victini and the Dark Hero - Zekrom (ビクティニと白き英雄レシラム / ビクティニと黒き英雄ゼクロム), Carlita's Sazandora (カリータのサザンドラ) & Janta's Golugh (ジャンタのゴルーグ) will be distributed at McDonald's and via Nintendo Wi-Fi Connection in Japan.
The Pokémon will be distributed at participating McDonald's locations wireless from
June 17th, 2011 until July 7th, 2011 and then on Nintendo Wi-Fi Connection from from
July 8th, 2011 until September 8th, 2011. Players that have Pokémon Black can download Carlita's Sazandora while players of Pokémon White can download Janta's Golugh. Further details have yet to be revealed.
Source:
http://shellspider.blog101.fc2.com/blog-entry-682.html