if they fall behind the PS4 and the XBO by the end of 2014 then they are really in trouble imo, the Wii U only has a slight lead right now (nothing like what the XBOX 360 had over other consoles in the last gen), if that lead goes and the PS4/XBO are selling more consistently through pretty much all of 2014 then they are in serious trouble, right now I wouldn't predict more than 20-30m sales lifetime for the Wii U, unless the big franchise games can turn things around and maybe a price drop as well, then I see no real reason to revise that anytime soon.
(for reference I predict PS4 sales will top 80m lifetime, and XBO to top 40m lifetime)








