If any newcomer is guarantee a spot in Smash, it is King K. Rool. Probably the most wanted newcomer, definitely in the Top 5 overall, has the potential for an awesome move set, and would fit right in. I can't think of any significant that could keep him out.
Every other character not already in (cut or newcomer) I feel has at least one barrier that could keep them from playable status. Whenever that is not being popular (overall or at least in a certain region), not having the potential to stand out as unique, not being adaptable/contributing to balance, comments made by Sakurai that puts doubts on their inclusion, frame issues (which I felt kept Ridley from Brawl), or third-party status, any potential newcomers, even the very likely ones, could fall into one of those pitfalls. King K. Rool suffers from none of these and because of this, I have no doubt that he will be in. A bold stance indeed, but I'm seriously willing to bet a small amount of money on his inclusion in Smash 4.
HyperFalcon's #100799 said:
Glad to see you again.
Diddy Kong's #100804 said:
Words cannot express my love for lions
Simba is where it's at son! Lion King for SNES was an amazing game, and your childhood wasn't complete without playing it!
I thought the Genesis version (which I played) was rather mediocre. The music was good and so was the visual, but the rest felt bleh.
Holder of the Heel's 100811 said:
Ah yes, some Mii love! He would be in my top 10 for sure. I think some people believe they'd be too much of a joke character in SSB4, but I feel that even if that is true, doesn't mean they can't be viable compared to the others. Mii just seems to make so much sense to me, I agree entirely.
I really hope Mii's do get in. They could not only let us play as characters that never made it in, but also allow us to bring Smash to a new level of enjoyment. As of now, Mii's are the only character that comes close to Mega Man in terms of how much I want them in, not only because they deserve it, but because they would be tons of fun.
Holder of the Heel's #100869 said:
And interesting SSBF, King K. Rool dominates there as well. D: And 9 Ghirahim... that does my heart good. :D And he got the same as Geno? Very strange. Mega man definitely stands out as the third party newcomer there. Good Paper Mario fanbase there too, probably bigger than you can get here. (Granted, top ten is asking for people to pull out a lot, but most wouldn't even put him in a roster here, same with Ghirahim.)
For some reason, GameFAQS seems to love Waluigi a lot. Not a terrible choice, but I feel as there are much better choices to go through before they pick him.