It has to be 3D Mario. Odyssey is almost 7 years old and has sold amazingly. Nintendo used to launch hardware with Mario games but hasn't always. Wii, 3DS, and Switch had no Mario launch games. Game Boy Color and GameCube kind of did when because of Game and Watch Gallery 2 and Luigi's Mansion.
3D Mario is the kind of game that will move hardware. Just about the only other game that makes as much sense to launch with Switch 2 or in the launch window is Mario Kart 9.
I do think we'll see a new IP. Many Nintendo platforms have launched with new IPs (SNES, Wii, 3DS, Wii U, Switch, to name some).
Lifetime Sales Predictions
Switch: 161 million (was 73 million, then 96 million, then 113 million, then 125 million, then 144 million, then 151 million, then 156 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 48 million (was 60 million, then 67 million, then 57 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima
