It's not a Nintendo console without a Mario Party or two and today at E3 Super Mario Party was announced for the Switch.
Super Mario Party will allow you to make two Switch tablets interact by placing them near each other. Leading to a lot of crazy new multiplayer configurations, like laying two Switches on a table and having an object move from one to another, or setting up two systems back-to-back for interactive mini games.
Mini Games shown included a home run tournament, a tank game, cooking, a motion control-powered racing game, and much more.