@OP: I agree (if I understood correctly what you mean). It could reach 7M TOTAL sales by the end of the year (or one week later, by Epiphany and Orthodox Xmas), if the small, but nice boost it's enjoying since Pokemon launch (oops, after Zelda launch, mixed up 3DS and Wii U boosts ) will scale up enough during Xmas season, but selling 7M during 2013 alone looks quite unlikely.
Anyway, if this boost scales up well and the after Xmas drop will be normal, not excessive, I'd consider Wii U safe, out of danger.