Yikes. Between this and SSB4 both having 3DS versions, it's like someone REALLY doesn't want the Wii U to sell.
Anyway, Tetra and the King of Red Lions are going to be new additions to the roster, and they'll be added to the Wii U version as well (some people claim you need the 3DS version to transfer them to the Wii U version, but I don't know how accurate it is). inb4 they're both darkness-elemental. Just kidding, they're probably both going to be water or something. Which would be good, because the existing Water sets are AWFUL.