Zelda, New Splatoon and Mario Kart, and possibly new 3D Mario. Even if that's all it has at launch, that's a monster. Third parties will likely have some ports at release too.
Guaranteed you'll eventually get Pokemon, Yokai Watch, Animal Crossing, Ace Attorney, Monster Hunter, Kirby, Smash, Fire Emblem, Etrian Odyssey, SMT, Warriors, Mario Maker, Metroid, Donkey Kong, Sonic, Bravely Default, Theatrhythm, Hatsune Miku, Minecraft, Dragon Quest, Pikmin, Luigi's Mansion, Mario and Luigi, Mario Party, Mario Sports titles, Professor Layton, and Bamco's Dragon Ball games
Even if Splatoon and Mario Kart are just "upgraded ports" the new content in the videos make them pretty new. How do you make a new Mario Kart? You add new racers, new tracks, and possibly a new mechanic. We saw King Boo as a racer, and the fact you have 2 weapon slots now. Looks new enough to me. Splatoon has new character models, new clothes (which have stats), and new weapons. That's new enough to me.
These are upgraded versions of some of the Wii U's best selling games. They -should- do even better this time just because of how much larger their audience is. Even if they only appeal to the audience that used Nintendo Products last gen, the combined platforms gives them a potential consumer base of 55-70 million, compared to the 13million that had a Wii U. The Nintendo Switch could be the first console in history where its major ports of last gen games sell better than the original releases across the board by virtue of how poorly the Wii U sold.