This is a weird one, but I’d love to see a reimplementation of the sensor bar. The gyro controls haven’t cut it for me. I like how the Wii U game pad had the sensor bar built in to the bezel. The real engineering nightmare would be squeezing IR cameras into the top of the Joycon
Record videos longer than 30 seconds, and for ALL games. As it is now, the Switch can only record the last 30 seconds of gameplay (which, in itself, is really cool because it works retroactively) and if you want to make longer videos, you either need to record consecutive clips and edit them on a different device, or you need a capture card. And it only works for some games to begin with - The Witcher 3 for example does not support that feature. You can take screenshots, but no videos.