This is kind of a unique first in Nintendo's gaming history, for the first time both their handheld and console divisions are not doing very well in the big US market. During the GCN/GBA days, the GCN never sold as low as the Wii U and the GBA was performing great until Nintendo had to start phasing it out in favor of the DS. 

The 3DS is sputtering now to 20k-ish weeks after a dissapointing holiday season last year (even with Pokemon X/Y and Zelda: LBW), one that was apparently (according to Iwata anyway) their worst holiday season in North America in a long time. 

The Wii U continues to sell horribly, even though the baseline is up this year, it's still far short of what the GameCube was selling even post Mario Kart 8. Case in point the GameCube sold 100k for August 2003, while the Wii U in the post MK8 honeymoon sold 59k for August 14. The Wii U has only beaten the GameCube in monthly sales once over a period of like 24+ months. 

Why is the US market so cold on Nintendo? Certainly they haven't invest a lot in Western development. Certainly the casual boom has been co-opted away from them by Apple/Android devices. It seems like the tablet boom has also stabbed them through the heart with the kids market as well. 

This may well be the biggest challenge Nintendo has ever faced in the gaming business. 

The amiibos are their last shot to sell at least decently this gen. If they can make their characters popular again, the game and console sales will increase as well.

Games, games, games.

Yeah they badly, badly need amiibo to be a hit. 

And I think it will do at minimum quite well for them, though the question I wonder about is whether it will be largely Nintendo hardcore fans buying (lots) of them as opposed to really expanding the userbase to new kids. 

Kids (or more likely their parents) may be more content to buy their kids Skyladners or Disney Infinity on their existing PS3/360/Wii rather than pay $300 to have to buy a new set of toys with. 

Good point. Nintendo needs to market it correctly for the kids who haven't gotten into Skylander or Infinity (or super rich kids). If the toys are pretty cheap to make, they might be able to profit again without even drastically raising console/game sales. I really hope it becomes a win for Nintendo, but it could go either way...

Nothing.
Nintendo has already given up on their home console business. They will try to extend the 3DS live with the new edition and come with a really new idea or concept afterwards. Fusion idea seems likely.

To why the Wii U will be lucky to sell 15 Million:
Nintendo never really tried to sell it. They didn't care to plan, market, consult even their own people and generally think hard about what the console would or could be.

The 3DS is likely failing to sell great, because of the reasons you listed.

Games and Smash Bros + October-dec.

I mean, this year they had Kirby and Yoshi and Tomodachi life.

No big hitters..............................................

Give up.

Someone had to say it ... 

I still wonder why so many people are betting on a non gaming product to sell a console. 

Price Cut! And since a new 3DS is coming shortly, Now would be a great time to capitalize on a holiday season bundle or price cut... or both.