I think the animation look a bit more realistic, and I like how they've added in newer attacks

too.
The 3DS version supports the Circle Pad Pro add-on (for the camera). I don't know if it uses the touch screen for anything though.
A lot of people criticize the Wii U's game pad screen because if it's needed to play the game effectively, you'll have to take your eyes off the screen. Even for a second whilst playing monster hunter could cost you the quest. I just hope that the the game doesn't hinge on that touch screen >.>...