NINTENDO is definitely riding the nostalgia like never before, but with such a great library of classics who could blame them?
They should make sure a considerable amount of care goes into making their back catalog available to newer generations, but I would agree that NINTENDO ought to continue to focus on great new experiences both in the triple A sense of the word as in the crazy 'gimmick' sense of the word.
If NINTENDO wants to cater to kids again, they need that new line of classics.
The gaming landscape has vastly changed however, and kids usually go for the more edgy stuff like GTA or Tekken or Battlefield.
Heck, now that I think about it, I know I did before I switched to NINTENDO.
Anyways, my view:
30% back catalog preservation/emulation
40% Triple A type of experiences and smaller projects
20% Crazy Gimmick shizzle
10% Pure Mario