As others have said, the Wii U doesn't need another first party Nintendo platformer right now.

I'll buy the game, likely on day 1, and will most likely love it. But the Wii U could use a little more variety right now and Retro is an extremely talented studio that probably could have brought something a lot more 'fresh' to the table. Ever since the Metroid Prime Trilogy ended I've really wanted to see what they could do with their own original project.