Wii U really isn't failing as much as everyone is making it look like it's failing.
it's not doing great, but it's really not failing. and I have a feeling it will do much better this holiday season. additionally, quite a few extremely successful franchises are releasing the next installment in their series next year, like Mario Kart and Super Smash Bros. if people still get attracted to that stuff like they always have in the past, I can guarantee you the Wii U will be doing better.
but I'm also not expecting the Wii U to be extremely successful compared to the Wii either. The Wii was ridiculously successful and it's going to be hard to one-up it, whether or not anyone thought it was a good console or not hehehehe