I wonder if the game will have the same graphics as Catherine. I surely love that style I just hope they don't drop the 2D artwork when the character have their reactions. In a small comparison, it's like Atelier Ayesha which dropped their 2D artwrok. Sure it's a natural progression if the company whats to make better 3D models but their artwork is so beautiful it would be a shame not to have anymore.
Maybe it will depend on the tone of the game. Looking back Nocturne and DDS didn't have 2D art and it doesn't seem like people missed them but again, you don't have a bunch of scenes of the characters just having fun in them.