Hey! Look what I found! It's a new leak/rumor that sort of piggybacks on the Ryu/Roy rumor! Basically, if you don't feel like reading the entire article, which is admittedly pretty long, the two big takeaways are:
-There's 5 unoccupied character slots in Smash 4's code. That means that, in addition to Lucas and possibly Roy and Ryu, we can potentially get two other DLC characters.
-There are 7 unused stage slots, and one of them is probably going to be a Kirby stage of some sort, because a lot of Kirby tracks were found in the game's code, as well.
If I'm not mistaken, the Roy and Ryu rumor has some pretty solid ground to stand on, since at least 5 other unique claims have been made since the initial one. Also, Roy makes sense to me, personally. I mean, he's a clone of Marth, so he wouldn't take too much time to develop, and I believe he has the strongest following of the remaining Melee vets, as well as one of the strongest followings of any cut veteran.
Ryu is a little out there, especially since Capcom already has a rep, but he seems like a reasonable addition. Licensing won't be as difficult, since Nintendo is already working with Ryu's owner, and it could be pretty interesting to see how a traditional fighter would transition into a game like Smash. Now, granted, I don't play any other fighting games (Pokkén Tournament will change that), so I know next to nothing about Ryu, but I'm still intrigued by how he would work in SSB4.
Also, Wolf is pretty much a shoo-in at this point, so, assuming Roy and Ryu are actually coming, that leaves one other DLC character, at least at this point. Obviously, if this leak turns out to be true, then that last character slot would go to the DLC Ballot winner. I think that it all lines up pretty nicely, and I'm inclined to believe that all of this is true, but I think that I'm going to keep sitting on the fence until more evidence surfaces, be it for or against the leak.