Zelda/Mario/Mario Kart plus a Switch is a great Christmas proposition.
If Nintendo can just ride the hype they got with the Classic, then Zelda through the summer until Mario hits without too many "gathering dust" comments, then they may have a hit on their hands.
I wonder how third parties will react to a success. I hope we don't just see a bunch of downgraded ports. The theme running through Nintendo's recent successes is a return to the attitudes of the 8 and 16 bit eras. That may mean virtual console (done right), it may mean collections of old games, like with Mega Man, it may mean reimagined versions of old games, like Sonic Mania and Blaster Master, it may mean new retro-style games, like Shovel Knight and it may mean modern-style games with old school inspirations, like Breath of the Wild.
Ideas I would like to see include (although these are obviously mainly first party):
Mario Maker port or Mario Maker 2
Zelda Maker
NES Remix port, NES remix 2 or SNES remix
Castlevania Collection
New Metroid
More old-style RPGS - Maybe a Chrono trigger or Secret of Mana game or even a FF VI style FF game.
I concede that stuff like COD and FIFA is probably necessary but I don't think those games add much. Anyone buying a Switch to play stuff like that, or Skyrim is probably going to be disappointed unless they are focused on portable mode.