That all changes on April 3, over a year since the system launched in Hong Kong, as Nintendo just announced that the regional eShop will go live on that date. The Nintendo Direct stream will run about for about 30 minutes. Most of the spotlight will presumably be on the Nintendo Switch, but we reckon the Nintendo 3DS may yet surprise us.
Mario Tennis Aces is planned for a 2018 release on Nintendo Switch; it's likely we'll get an exact release date tomorrow. Nintendo is capable of filling that window of time with a lot of announcements, both big and small.
I'm sure there are plenty still hopeful for a GTA V announcement or Diablo 3, but it's always very hard to bank on third-party enthusiasm, even with the system doing as well as it is, it may be too early for bigger third parties to go all-in on the system, but you never know. A reported "director's cut" of the 3DS/Wii U Smash games (with some new characters) has been the subject of rumors since the end of 2016, months before the official release of the hybrid console.
Be sure to keep your eye on Nintendo Enthusiast for updates on tomorrow's Direct.