I'm going to quickly run down a list of desired characters and tell you why they are garbage compared to Takamaru.
King K. Rool: Probably the worst addition you could make to Smash. He is a poor man's Bowser, and one of the most unoriginal bad guys in gaming. We already have enough heavy brawler characters who are much more imaginative. Also his entire motive is to steal bananas. Fucking BANANAS.
His boss fight in DKC has is ridiculously lame. FINAL SMASH: Throw crown.
Dixie Kong: What if Diddy Kong was a girl? That is the extent of how much thought was put into the idea of Dixie Kong. She's got HAIR ABILITIES WOW. She can haircopter over gaps. That's way cooler than a barrel jetpack!
Daisy: Bob-Ombs are better developed characters than her. She barely gets into Mario Party games, and if Nintendo dumps her for Rosalina any chance they get.
Shulk: Heir to the Monado? More like heir to the worst main character design since Vaan in FFXII.
Chorus Men: Donkey Kong's final smash called, it wants its gimmick back.
Dark Pit: I can't believe this character actually has a chance of getting in. Yes, I know "evil" versions are a staple in many fighting games, but his inclusion would be a clear case of Sakurai playing favorites instead of trying to make the most diverse and interesting roster possible.
Hades: See Dark Pit.
Chibi Robo: Chibi Robo looks like something a three year old would draw. It is completely void of any character and its entire gimmick is that its small. Not to mention it has the most boring abilities you could imagine like cleaning and plugging itself in. The point of his game is to collect happy points. HAPPY POINTS.
Ray MK-2: He looks like one of those cheap knock off Gundams you find in Japanese capsule machines. He also has the same gimmick as Chibi Robo in that he's just a small robot. What's he gonna do, shoot lasers? Pit already stole that.
Bandana Dee: I refuse to even acknowledge this character.
Ghirahim: Ghirahim was only cool when he revealed his true form. Before that he was a stereotypical effite villain who did nothing. Neutral special: Stand there. Side special: Wave hand around.
Ridley: Nothing bad can be said about this majestic beast.