Paid Online details
Some nice 3rd Party surprises
Fire Emblem Three Houses details
Something Bravely related
New Super Mario Bros U Deluxe
New Smash character (either Skull Kid or Issac) with a beta on the same day as the paid online service
Side note: I don't think Star Fox Grand Prix is gonna show up during it, I think that will be a early 2019 reveal since according to some of the leakers it is set for a Summer 2019 release.