Xbox One will take 2nd place easily. How people can't see this is beyond me. It deserves to take 2nd as well.
Wii U > XBO for me but Wii U doesn't really deserve much success. It was handled terribly and gets like 15 games a year. Even if those 15 were amazing, it can't ever have the diversity that the XBO will have.
Once the games start coming, Wii U will be passed. It's inevitable.