Ubisoft released a brand new trailer for Splinter Cell: Blacklist that details the threat Sam Fisher and Fourth Echelon will face in the upcoming game. Make note that the threat on Wii U won't include offline cooperative play.
The trailer itself reintroduces the terrorist threat behind the Blacklist, "a new kind of war" that results in widespread attacks by "The Engineers." With the president on the brink of declaring war, it'll be up to Sam Fisher and his cohorts to stop it.
Back to that small issue with Splinter Cell on Wii U: producer Liu Jun told Nintendo Life that the game will launch on PC, Xbox 360, PS3, and Wii U on the same day, but Wii U owners will be without offline co-op play. Liu said that the feature was cut specifically to keep all platform launches in line, but that the developers think "Nintendo gamers will be really excited to get the game at the same time as other consoles."
Wii U players will still get to enjoy the full game on their GamePad screen (while someone else takes over the TV) and I haven't been really dependant on couch co-op for some time now, so I don't see why this would effect the overall quality of Blacklist.