Nintendo released a new promotion video from the upcoming Splatoon 2 during the ARMS Direct 2017.5.18. In the video you can see the new battle scenes with the hero characters and as you can see the game is nearly finished.
The new Splatoon 2 will be available from 2017 Summer in all regions only on Nintendo Switch. It should be noted that on the release day in Japan (July 2) you can buy the official Splatoon 2 designed accessories for the console such as the Joy-con covers, pouch cases, etc. The game will be available even in bundle package with a Switch.