The new game will feature '2D artwork' but will still take 'full advantage' of the 3DS.
http://www.nintendoworldreport.com/news/25724
Marvelous is working on an original 2D 3DS game that will take advantage of the system's 3D capabilities. In an interview with Siliconera, Yoshifumi Hashimoto, credited producer on many Marveolus Entertainment published titles including Muramasa: The Demon Blade and Rune Factory, revealed that they are working on a new title.
Despite previous rumors, the game is not a a re-release of Muramasa, which was developed by Vanillaware and only published by Marvelous.
"It's not Muramasa, but I’m working on a 3DS title that has really incredible 2D visuals while taking full advantage of the 3DS' capabilities,"- Hashimoto explained to Siliconera.
Great news! I was afraid Marvelous had abandoned Nintendo systems after some of their Wii games failed commercially.i too was afraid of that, good chance this might be a game i must have, i love all the games that type design, and to the same extent, games that they produce. i think they quickly became my favorite third party software team after i started playing muramasa and then arc rise the fantasia