I've followed this thread and threads for the other popular characters for a while now, but I've never actually felt compelled to post in here now. I feel like some clarification is in order regarding Shovel Knight, since people seem to want to go out of their way to discredit him in thsi thread with any reasoning they can think of, even if it doesn't really make any sense.
People say Shovel Knight isn't "Iconic enough." or doesn't have the legacy or relationship with Nintendo to be in Smash, which would have been a fair assessment like 7 years ago when Brawl came out. The reason there are so many rules in regards to who gets into Smash is because the developers need guidelines for who to consider with their limited development time. They need to make the most of their time and make a Roster full of both characters people love and characters that will surprise them. They need to do the best they can with the time they have.
But with Smash 4, the game has changed, so to speak. A majority of the newcomers are characters from relatively recent games and franchises instead of how it was before. It's only natural and it makes sense. Brawl covered pretty much every popular Nintendo franchise in some way with the exception of maybe Animal Crossing, which was immediately fixed in the next game. Say what you will about the game, but the roster was excellent, all things considered. There was something for everyone in there.
Smash 4 has a shift in focus to cover new or less recognized games and franchises, to the point where Greninja was pulled from unfinished concept art just so they could have him ready for the game. This makes a lot of sense to me. I'm glad Nintendo is finally showing more support for their newer/lesser known games and IPs. Somebody like Shulk wouldn't have made Brawl.
You also have to consider that DLC eliminates a lot of the limitations that came before when trying to develop previous games. They don't have to worry about a deadline anymore, which opens up more possibilities for who they can consider. Roy isn't a character you'd worry about including in the base game, but as DLC? why the hell not. He's easy enough to make and the fans will like it. DLC opens up the door more than you make think. The rules that applied when composing the roster for previous Smash games don't apply anymore. They can go wild since they have lots of time to do whatever, and I hope they take advantage of that and go with some crazy choices.
Combine all this with the fact that the ballot very clearly openly welcomes ANY video game character, not just Nintendo, and I think Shovel Knight makes a lot of sense. I can't think of many other indie games that have been such a huge hit. It'll build Shovel Knight up as a franchise, open the door for indies all over, and strengthen Nintendo and Yatche club's relationship.
It's also pretty blatant that he's popular and wanted for the game. The "he's just a fad" complaint never made any sense to me. It implies indie games are lesser games, and Shovel Knight's status as a hit and cameo spots in so many other games doesn't mean anything. It underplays Yacht Club's accomplishments, and it feels like a complaint one of K Rool's own detractors would come up with. Every big indie game has been fondly remembered for years by gamers, so I don't see how Shovel Knight would be different.
Besides, Sakurai has been breaking all the "rules" the fandom seems to have come up with on who can and cant get into smash since the game was announced. I honestly don't think they apply much anymore as most of them are broken by one character or another.
Now, in regards to K Rool himself's chances, I was pretty sure before that he had a good chance, considering all the people voting for him, but when thinking all of this stuff over, now I think it depends purely on whether or not he has a future in the Donkey Kong franchise or not. Smash 4 seems to prioritize new characters over old favorites, which, as I said before is very much a good thing, but if King K Rool has no future in the Donkey Kong franchise while Nintendo continues to look forward and open up the door a bit more, he may be left in the dust. We'll have to see what happens with Donkey Kong from here, but I get the feeling the only way he'd make it into Smash 4 is if Retro is working on something with him in it.