A LOT of things in Super Smash Bros. for Wii U

Characters
Ness (3DS unlockable; Wii U default)
Jigglypuff (3DS unlockable; Wii U default)
Ganondorf (3DS unlockable; Wii U default)
Bowser Jr. (3DS unlockable; Wii U default)
Mewtwo (As DLC when you get both versions in Spring 2015)

More Wii U Stages
Big Battlefield
Mario Circuit (Mario Kart 8)
Mario Circuit (Brawl)
Delfino Plaza (Brawl)
Luigi's Mansion (Brawl)
Yoshi's Island (Melee)
Jungle Hijinks
Congo Jungle (Only N64 stage that reappears for the 2nd time)
75m (Brawl)
Temple (Melee, but was already confirmed)
Bridge of Eldin (Brawl)
Norfair (Brawl)
The Great Cave Offensive
Lylat Cruise (Brawl)
Port Town Aero Drive (Brawl)
Skyworld (Brawl)
Wrecking Crew
Wuhu Island
Miiverse

Wii U-exclusive
Special Orders (Master Orders and Crazy Orders; Mostly everyone was right)
Smash Tour
8-Player Smash (We already know)
Event Match
Special Smash
My Music (Which we know already)
Clear movies 
Master Fortress (Classic on harder difficulty)
Controllers: Wii Remote Plus, Nunchuck, GamePad, Classic Controller, Classic Controller Pro, Wii U Pro Controller, GameCube controller, Nintendo 3DS
Final Smash trophies
Trophy Box
Photo Studio
Masterpieces (You can get the full version to the Eshop)
Amiibo 
Paint

Mode differences
Classic (3DS, paths; Wii U, skill-based)
All-Star (3DS, Past to Present; Wii U, Present to Past)

This, Super Smash Bros. for 3DS, and Mario Kart 8 are the games I really want in 2014.