We don't know much about whatever Ubisoft has planned for their Assassin's Creed title on the upcoming Wii U. A Ubisoft representative, however, has confirmed that the title will not be a port of Assassin's Creed: Revelations.
When asked about this very question in an interview with the Swedish site Aftonbladet, Yves Guillemot responded, "No, not Revelations. For the future."
Your guess is as good as ours as to what that means, but it seems perfectly clear now that Revelations is not going to be ported to Wii U after all.