Quick response to various posts that interested me (without quotes):
The Excitebike track was likely added to Mario Kart 8 because of Excitebike: Bun Bun Mario Battle Stadium... It's a pseudo-classic track, in that regard.
Most recognizable Rhythm Heaven character:
Eat your heart out generic Chorus Kids nobody ever knew about before rumors.
King K. Rool is typically portrayed at twice the size of Donkey Kong... I've been saying it for years, but if Ridley is "too big", K. Rool is way too big.
Whether Ridley was intended to be playable can't be substantiated... But it also feels to me like the development team tried to work things out with the character. I don't know why they decided against it, but the scenario that makes sense to me is they attempted to implement Ridley as kind of a.. "Giga" sized character, but it ultimately didn't work out (even Giga Bowser isn't fun to play as on narrow stages). I doubt his exclusion had anything to do with 3DS capabilities.
More third-party characters would be great, honestly. There's a string of about ten characters that, in my opinion, represent the best of gaming throughout various generations (that haven't made it in yet). These are iconic characters or franchises or titles that deserve to be acknowledged in some regard: Frogger, Q*Bert, Final Fantasy, Street Fighter, Crash Bandicoot, Spyro the Dragon, Rayman, Tomb Raider, Skylanders. As I see it, those are the most significant third-party titles spanning the entirety of video gaming history... I just want to make it clear that there are other First-Tier gaming icons, but they happen to be first or second party to Sony or Microsoft. Popeye, James Bond, and Mickey Mouse are the only non-gaming characters with enough clout to stand among the others (Without Popeye there wouldn't be Mario, GoldenEye 007 defined the FPS genre, Kingdom Hearts is a massively influential franchise). As far as including third-party characters in Smash Bros., I think they should also consider characters or franchises which have had previous crossovers with Nintendo's properties... so Soul Calibur, Bomberman, Dead or Alive... those should all have special consideration.