The World Ends with iOS >:(

All I really hope

Is that it's still pixel art. No god damn 3D models, PLEASE.

If it's a 3DS game, I don't want to be a huge downer, but I seriously doubt it will have sprites. We're still in the realm of "Developers NEED *System gimmick* regardless of whether they're appropriate", and 3D wouldn't be as noticeable with sprites. That said, I can't even imagine I would want to try and keep myself in the 3D sweet spot, while controlling both of the characters.

And I seriously doubt they're going to make a 3DS game which doesn't support 3d.