Not a confirmation, but this forum suggests a Wii version is real.
The Call of Duty: Black Ops II forum page includes a Wii forum, suggesting the existence of a Wii version of the recently announced first person shooter.
Call of Duty: Black Ops II was officially announced yesterday, but a Nintendo version of the game was not discussed. However, on the game's official website, there is a forum dedicated to a Wii version of Black Ops 2.
This forum certainly suggests that a Wii version of the game is on the way, but does not officially confirm it. When more information is revealed about Call of Duty: Black Ops II at E3 2012, we are bound to learn more about what platforms it will land on.
We've reached out to Activision for an official comment.