It would seem that Call of Duty: Black Ops II will be getting a release on Wii U, if the LinkedIn profile of one QA tester from Activision is to be believed. Uncovered by IGN, this profile belongs to someone named Randall (though details on the account have been changed since the discovery), and claims that he performed "QA testing on PS3 and Wii U" while working at Treyarch. His profile also said that he did multiplayer testing while working with the team, along with "ad hoc testing, and regression."
He's been performing those duties since May, which suggests that the Wii U version of Black Ops II has been in development since at least then. It wouldn't be much of a surprise to hear that Black Ops II is in development for Wii U, as its predecessor appeared on the original Wii. Indeed, many Call of Duty titles have been featured on Wii too, with the most notable exception being Modern Warfare 2.
Most of those ports were pretty solid too, if not as fully-featured as their Xbox 360 and PS3 counterparts. That should all change with the Wii U though, as it won't suffer from the same hardware limitations the original Wii did. Still, that's assuming that Black Ops II is coming to Wii U in the first place, and even though we've received some pretty solid evidence that it is, neither Activision nor Nintendo have made any announcements yet.
We have a feeling that it is coming, but Activision may be waiting to announce it until Nintendo unleashes more details about the Wii U. Remember, much to dismay of players, Nintendo still hasn't talked system specs, pricing or even given us an actual release date yet, despite the fact that we're supposedly only a couple of months away from launch. Once that information is out there, Activision will probably announce Black Ops II. For now though, it remains confirmed only for Xbox 360, PS3 and PC, and it's hitting those platforms on November 13. Stay tuned for more details.