According to this UK Nintendo store page, two DLC packs are heading our way in the future, one in November, one in May 2015. They contain two new cups each and also three new characters too. They also expand the characters from Mario games to Link from The Legend of Zelda and also the Villager and Isabelle from the newest installment of Animal Crossing.
These DLC packages aren't free though. They come at a price of £7.00 each.
Nintendo UK Store said:Each Add On Content pack will contain two new cups, each with four courses, which, in total, increases the number of available courses by 50 percent. The Add On Content packs include classics like Wario’s Gold Mine from Mario Kart Wii, as well as new courses, some taking place in the worlds of The Legend of Zelda and Animal Crossing. New vehicles will also arrive with each pack, including the Blue Falcon kart representing the F-Zero franchise in the first AOC pack.
Mario Kart 8 Pack 1 - Released: November 2014
Pack 1 includes:
Mario Kart 8 Pack 2 - Released: May 2015
- 3 Characters: Tanooki Mario, Cat Peach, Link
- 4 Vehicles
- 8 Courses
Pack 2 includes:
As a bonus for purchasing both packs - as a bundle or separately - you can get eight different-coloured Yoshis and eight different-coloured Shy Guys that can be used right away.
- 3 Characters: Villager, Isabelle, Dry Bowser
- 4 Vehicles
- 8 Courses
Source