Xthe Legend of Zelda X
Forget the new "NX" hardware, Nintendo devoted just about all of its E3 to The Legend of Zelda: Breath of the Wild (in order to hopefully sell the NX when it launches next March). And the huge, open-world game is taking all hands.
Monolith, the studio behind the open-world JRPG Xenoblade Chronicles X, is helping out of Breath of the Wild.
"Yes, they are involved in this Zelda," Shigeru Miyamoto told Game Informer. "People from Tokyo and Kyoto are working together on this. There is a team of over 100 [from Monolith Soft and Nintendo] helping work on this project, and their work has really been helpful."
This isn't a new partnership, however. Monolith also contributed to development on the last main Legend of Zelda, Skyward Sword.