Ubisoft has just recently announced some details surrounding the Wii U version of Ghost Recon Online. Including;
Also there will be a feature called "Ghost Feed", which will run on the Wii U controller's touch screen, and will basically be a version of the Xbox or PS3 Friends List, and will show what your friends are doing as well as any scheduled events. As far as gameplay goes, the Wii U screen can be used to select weapons and aim missile strikes.