In about fifteen minutes, Nintendo are going to show off what they call "a new interactive experience" for the Nintendo Switch.
The feature, which will be livestreamed at 0900 AEDT / 0600 AWST / 0830 ACST / 0800 AQST / 1100 NZST, is "specially crafted for kids and those who are kids at heart". That's all the information Nintendo's released, although some have speculated that it might be related to some of the quirkier use cases outlined in the original Switch patents.
The official livestream link is below.
Update (0902): A video has already appeared online for something called "Nintendo Labo", which is billed as a "new line of interactive build-and-play experiences that combine DIY creations with ... the Nintendo Switch".