To be honest I think the Wii U is a great product that was marketed very badly. When it came out most people didn't even know about it and it had no good games.
The Screen on the controller is great for when somebody else needs to use the living room tv, lets say a dad want to watch football when his children is playing Mario Kart of something, even works with older wii games as it can be used as a screen for old Wii remotes.
The only thing the Wii U does not have atm is 3rd party games, which for me as a PC user isn't important. The PS4 and Xbox One are not of interest to me, I'd want to play the Halo collection if it worked and the only thing on PS4 I'd want to play is The last of US and I owned that last gen. The Wii U has a lot of great games, the new Mario Kart and Smash Brothers are fantastic and I really want to buy Beyonetta 2.
The only thing really holding Nintendo back ATM is a different hardware spec than everyone else which makes it very hard to get 3rd parties interested when combined with their poor sales, too much work for a relatively small number of users.