I'm kind of curious what Nintendo will do once they're officially done with the Wii U. There will be a lot of DLC that future gamers will be unable to purchase when eShop is eventually dropped, so I'm curious if Nintendo will release something like those "GOTY Editions" (like how they have almost all the DLC and etc.).
I really hope they spend more time working on 5mash, though. Sm4sh is amazing (and I hope they keep the art style), but a lot of parts felt unfinished and bare. Master Orders/Special Orders REALLY could have been something amazing (like Tower of Smash), there were WAY too many returning stages rather than new stages (and some of the new "retro" stages just felt lazy. I mean, Pac-Land could have been all 3D, not pixelated). The 3DS version shouldn't have existed at ALL (I have never picked it up since I completed it, whereas the Wii U version is a different story), and there were a TON of stages that should have been on the Wii U (Pac-Maze, Green Hill Zone, Magicant, Balloon Fight, Paper Mario). Classic mode on Wii U and 3DS could have been a lot better too. The Wii U Classic mode felt kinda lazy, the 3DS one was kinda pointless (you always go on the path with more coins, there's not really anything hard puzzling about that), and they both shouldn't have had the difficulty thing from Kid Icarus (yes, it was good, but it took way too much inspiration from Kid Icarus, when Smash is a celebration of Nintendo, not Sakurai). Ridley should have been a character (there is a good way to make him work if you've seen the Brawl mod), and the game should have had a lot less advertising (Woolly World, Mushroom Kingdom U, and Kalos PokeMon League).
Smash Bros. is all about Nintendo history, not promoting new games (unless you have enough stages for each series to do so).