For what it's worth, Namco Bandai has a credit as a developer in Mario Kart 8. I dunno to what extent, but hey. Maybe this Mario Kart 8 DLC really is them testing the waters for possible Smash DLC in the future. Probably just wishful thinking, but food for thought all the same.
Periodic updates are good for fighting games since they tend to last a long time. Doing it the way Capcom did it with Marvel vs Capcom 3 and Street Fighter IV isn't a good idea where updates, characters, etc. cost a ton and not having them locked you into the "old" version. Killer Instinct treats itself like the UFC or other sports where seasons exist and each season has a new experience - new characters and such. I don't know how much Killer Instinct costs - the web said $0? -, but if each season was $10 and the game lasted say, 5 years, it'd be a steal; 5 seasons, 5 years, and only $50. Probably not the price, but just a theoretical path.
Basically, Capcom's going the Call of Duty and other shooters route. Killer Instinct is going the "MMO" route. I wonder what Nintendo is going to do. Maybe something like Fire Emblem: Awakening with a couple of updates being free and others paid?
So what does this mean? It means SSB4 has a "finalized" roster or rather a launch roster with the potential of some characters being delayed or reworked during early development - Ice Climbers and/or Wolf possibly? It also means that SSB4 won't be the same game year after year. We might get, I don't know, Swampert, Sceptile, Toon Ganon, Zant, Paper Mario, Paper Bowser, Rundas, Gandrayda, Dusty, Kumatora, Raiden, Revolver Ocelot, Daisy, Toad(sworth), Krystal, Leon, and whoever as new characters. Oh, and different stages, challenges - daily, monthly, yearly -, etc.