If I may, I'd like to ramble again
The 5 most likely characters for SSB4
Geno-He was a character that was popular worldwide, and pretty popular at that. From what we have seen, he still stands as the most requested character. I suspect he wasn't in Brawl becuase he was skipped over (like some popular characters are) or problem with Square-Enix. If Nintendo can get everything though with SE, then expect him.
Ridley-He was the most popular character in the west, but he didn't make it. Many will say it was because of his size; I would say because he lacked enough Japanese popularity. He was a boss and planned for an assist trophy. I suspect he'll make it in the next go around.
Krystal-She was also one of the most popular characters, but she was left out, probably due to Star Wolfs insane popularity. One of Falco's secret taunts mentions her saying that she will be the next one to fight. It's not confirming anything, but it may at least show that Sakurai recognizes Krystal.
Saki-Sakurai made a very interesting mention on the blog.
There were many requests from users for his inclusion, and he IS pretty cool, so I did what I could to include him.
I think Saki is a character we never though as being that popular. If he was skipped over, it was because he was a Japan-only character. I suspect with Sion and Punishment on the VC that he may be in the next game. If not him, then Issa from Sin and Punishment 2.
Little Mac-He is a character that is not that popular, but seems to stay in Sakurai's eyes. He was planned to have a trophy in Melee and was an assist in Brawl. I think he may graduate into a playable character as the retro character for the next game. Punch Out Wii may also help his chances.