The crossover possibilities are endless. We could have a Rabbids/Worms crossover, although it's not a nintendo crossover. Although i do want to see a new fortune street game with Nintendo and Disney Characters and by Nintendo i mean characters from Mario, Legend of Zelda, Kirby and so on. I would add Pocoyo in a nintendo crossover, but he might be too young. Anyway, here's the fortune street list of my dream...
Nintendo Series:
Mario
Luigi
Peach
Bowser
Kirby
Waddle Dee
King Dedede
Meta Knight
Donkey Kong
Diddy Kong
Cranky Kong
Dixie Kong
Link
Zelda
Ganondorf
Impa
Fox McCloud
Falco Lombardi
Peppy Hare
Slippy Toad
Disney Series:
Mickey Mouse
Minnie Mouse
Donald Duck
Daisy Duck
Goofy
Pete
Oswald The Lucky Rabbit
Clarabelle Cow
Horace Horsecollar
Ludwig Von Drake
Scrooge McDuck
Chip and Dale
Huey, Dewey and Louie
Jiminy Cricket
Mortimer Mouse
Clara Cluck
Humphrey The Bear
Panchito Pistoles
Gus Goose
Jose' Carioca
(Let me know if there is more to add)
Stages:
Traverse Town (Kingdom Hearts)
Destiny Islands (Kingdom Hearts)
Hollow Bastion (Kingdom Hearts)
Oakey Oaks (Chicken Little)
Halloween Town (Nightmare Before Christmas)
100 Acre Woods (Winnie The Pooh)
Duckberg (Ducktales)
Kauai (Lilo and Stitch)
Cape Suzette (Talespin)
Corneria (Starfox series)
Venom (Starfox series)
Dinosaur Planet (Starfox Adventures)
Peach's Castle (Mario Series)
Bowser's Castle (Mario series)
Bomb-omb Battlefield (Super Mario 64)
Jolly Roger Bay (Super Mario 64)
DK Isles (Donkey Kong Country series)
K. Rool's Mechanical Island (Donkey Kong 64)
Dream Land (Kirby)
Cappy Town (Kirby Right Back At Ya!)
Hyrule Castle Town (LoZ Ocarina Of Time)
Kakariko Village (Legend Of Zelda series)
Kokiri Forest (LoZ Ocarina Of Time)
Dark World (LoZ: A Link To The Past)
Windfall Island (LoZ: Wind Waker)
(Again, let me know if there are anymore stages to add)