Other than skins and graphical textures, there is a Super Mario themed world.
There are a number of Mario references in this world (according to the map), like:
- the whole SMW world map at the bottom right corner
- Isle Delfino at the top right corner
and also:
- Peach's Castle from SM64
- Acorn Plains from NSMBU
- Bowser Lake from SMW
- Various statues (like Mario, Yoshi, Peach, etc)
- Sprite art
- World 8 as the Nether world
The whole world itself is designed to resemble a world map.
EDIT: This list is incomplete. This means there's more to this world.
These Mario references would overhaul the 'Reference' page. I think we should create a page with character skins, texture replacements, and information about the Mario-themed world. Maybe name the article either 'Minecraft: Wii U Edition' or just 'Super Mario Mash-Up Pack'.
There, finished.