I came in possession of a Wii U a few months ago (yay for random raffles...I'm the guy with long hair holding the system):
http://www.j1studios.com/what-went-on-at-j1-con-2/
And that caused my interest in this game to go skyhigh, since I didn't have to actually buy the system. I feel like they are keeping an eye on the 2D history of mario as they flesh out the 3D part. I felt like the other 3D Marios are too far removed what I liked about oldschool Mario.
Music-wise, I found Galaxy 2's OST very enjoyable, so I'm looking forward to hearing this one.