The new Super Smash Bros. will have, for the first time in series history, a staged themed around Paper Mario.
Game Director Masahiro Sakurai once again took to Miiverse to reveal the new stage, explaining that it's "made of paper, so strong winds will blow it away." So I'm guessing chunks of the stage will blow away at random times leaving gaping holes that you can fall through.
Sakurai also explained that "since the stage is paper, it transforms when it folds over and opens up again." Examples shown so far reveal Paper Mario locations from Sticker Star and the S.S. Flavion ship from The Thousand-Year Door.
Given that both screenshots are of the 3DS version of the game, I'm assuming this Paper Mario-themed level will also be exclusive to Nintendo's handheld. Last week, Sakurai revealed a Tomodachi Life stage also exclusive to the 3DS version of Super Smash. It, too, sounds really cool.