Nintendo will release extra episodes for Pokémon + Nobunaga’s Ambition through Nintendo Wi-Fi. The strategy RPG comes out on March 17 and the first episode which details the event on how Chosokabe Motochika and Mori Motonari became friends comes out on the same day.
On March 23, you’ll be able to download an episode about the Wandering Kabuki Kenji, a mysterious hero who saves you in the middle of Pokémon + Nobunaga’s Ambition. You can see the extra scene after you complete Pokémon + Nobunaga’s Ambition and see the game’s first ending. This extra scenario will only be delivered until April 13.
Nintendo also explained military commanders can be paired with different Pokémon, but there is an optimal Pokémon for each character. You can find the "best link" by checking the link percentage and if it’s 100% you have a perfect match.
Source
http://www.siliconera.com/2012/02/15/pokmon-nobunagas-ambition-extended-with-free-downloadable-episodes/
A nice touch to extend the game but I hope this game also has a New Game + option.