"New Super Mario Bros. 2" for the 3DS has proven that Nintendo isn't afraid to jump into the DLC game, and it looks like they plan on continuing the trend with "New Super Mario Bros. U". In fact, the game's producer recently revealed that they're already planning additional courses for the Wii U launch title.
Speaking in a special Iwata Asks session to celebrate NSMBU's impending US release, producer Takashi Tekuza explained that Nintendo already has plans for the game's future downloadable content. Thankfully these stages will be different than the DLC offered for "New Super Mario Bros. 2", but specifics have yet to be revealed.
“We're trying to think of ways of play that are different from New Super Mario Bros. 2, but we haven't made anything yet,” said Tekuza.
“The mechanism for adding courses is already there, so please stand by for an update on what they'll be like,” added Iwamoto.
You can read the entire New Super Mario Bros. U edition of Iwata Asks on Nintendo.com right now, but why not read our review first?