Nintendo going to be held (like every year) an online E3 event for the fans. The Nintendo Spotlight: E3 2017 will be aired in different times depends on the Time Zones. In Japan, you can watch it on June 14 at 1:00 (AM) with Japanese subtitle.
During the E3 event Nintendo going to introducing the upcoming big titles for Switch and 3DS like the ARMS, Splatoon 2, the new Pokemon games, the next SMT and the new games. The official E3 page of the Nintendo is already online.