I have a lot of faith in Marvelous. They've published a lot of my favorite 3rd party Wii games, including No More Heroes 1 and 2, Little King's Story, and Muramasa: The Demon Blade. They're a small publisher without a lot of money to throw around, which I think has led them to make games that work extra hard to be expressive and interesting.
It sounds like they'll be going the same route with the 3DS. Instead of going polygon-based like just about every other 3DS game, they're working on something 2D (though those hoping for a new Muramasa may be disappointed.) To quote the Marvelous Entertainment's Yoshifumi Hashimoto-- “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.”
I just hope Vanillaware is involved. They are one of the few studios out there today that make a game so pretty that I'll love it regardless of how well it plays. I just hope it's not a new Ikki Tousen game. I don't think I could handle the pervy-ness of bikini anime women popping out of a soup bowl at me in 3D.