Along with remastered courses from other Mario Kart games, there's another brand new track this time around. Yoshi’s Island takes inspiration from the SNES classic Super Mario World 2: Yoshi's Island. It will be part of the Fruit Cup along with the windmill- and tulip-laden Tour Amsterdam Drift (from Mario Kart Tour), GBA Riverside Park (Mario Kart: Super Circuit) and Wii DK Summit (Mario Kart Wii). Coming to the Boomerang Cup are Mario Kart Tour tracks Tour Bangkok Rush and Tour Singapore Speedway, along with DS Mario Circuit (Mario Kart DS) and GCN Waluigi Stadium (Mario Kart: Double-Dash!).
Meanwhile, there are a bunch more playable characters coming to the game. Birdo is the first of them and will return to the series when Mario Kart 8 Deluxe gains the next wave of tracks.
There are two more bundles of eight courses on the way to the Booster Course Pass. You can buy the DLC outright for $25. It's also available as part of the Nintendo service, which is $50 per year or $80 per year for the family plan. You'll need to own Mario Kart 8 Deluxe to access the DLC, of course. If you're one of the 20 people who don't already have the game on Switch, you'll be able to pick it up at a discount when it goes on sale at some retailers between March 5th and 11th.