This thing should get good Japanese 3rd party support, even the 3DS in Japan outsold the Wii + Wii U + GameCube combined.
Dragon Quest, Monster Hunter, Tekken, Resident Evil, and maybe Final Fantasy should be on board. We know Sonic is.
Western devs will probably wait and see, but the portable aspect of it makes it an easier sell too I think, Western devs have always liked Nintendo's portable userbase size, but they've never been able to port their existing engines because DS/3DS/GBA were relatively weak portables.
NX could change that so who knows maybe ports of games like COD and Madden NFL direct from their console versions are possible.
Nintendo games (all of them, no more split between two platforms, so Splatoon + Pokemon RPG mainline + Zelda: Breath of the Wild + Animal Crossing + Fire Emblem all one system)
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Japanese third party games (Monster Hunter, Tekken, Dragon Quest, Yokai, Final Fantasy?)
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Android apps (Candy Crush, Snapchat, Video Player, Music Player, Angry Birds, Mobile Strike, Game Of War, Pokemon GO)
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A good flow of content at minimum even without Western 3rd parties.