Here are my predictions:
-Last Gen>Current Gen regarding console sales
-Wii>PS4
-WiiU>Xbox1>NGC
WiiU is at the moment the best console to own considering games, network and how it runs. I personally have a Wii U and a PS4 and family & friends go for WiiU. That cannot be coincidence.
What is WiiU missing? Promotion and Marketing! Nintendo MUST focus on pushing its products intensively. It does push Mario Kart 8 well but can do better.
I think WiiU will do the same as PS4 at the end of this GEN. Many years lie till then, but just my prediction.
And to explain myself, till 3 million for me it is not a big difference.
Cheers :)