"On the whole, Nintendo is falling apart". Really? REALLY? LOL I'm sorry but.............*facepalm*
That statement alone was enough to derail the thread, honestly.
3DS might not outsell GBA? That depends entirely on how long they keep it on the market before releasing a new handheld. 3DS was the top selling system of 2013, and it honestly did pretty strong numbers in 2012 as well. It's STILL selling well right this moment (on par or better, week to week, with PS4).
Wii U might not outsell GC? A highly debatable point. It remains to be seen, but it's still highly debatable, and chances are likely that it most certainly will eventually outsell it.
"What can Nintendo do?" They can make and release games. They can partner up with third party devs, and get more exclusives. They can continue to lure the growing mass of indie developers to make games for eShop. And they can advertise the system better. That's all any company can do, really.
But "Nintendo is falling apart"? Not even close.