Greninja (Pokemon from X&Y),
Little Mac (Punch Out!!),
Lucina (Fire Emblem: Awakening),
Robin (Fire Emblem: Awakening),
Mega Man (Mega Man series),
Mii Fighters (Wii ___ series),
Pac-Man (Pac-Man series),
Palutena (Kid Icarus: Uprising),
Rosalina & Luma (Super Mario Galaxy),
Villager (Animal Crossing),
Wii Fit Trainer (Wii Fit)
Shulk (Xenoblade Chronicles),
Chorus Kids (Rhythm Heaven)
This list just makes way too much sense if you look at it with a professional mind; they're all logical choices, and relevant, and popular (some more than others). Try to remove any bias from your mind, and then really take a good look at the list.
You must remembert that Sakurai really isn't as unpredictable and crazy the Smash fanbase make him out to be; he's developing a massively popular Nintendo title under a multi-million dollar corporation, therefore business decisions are inevitability going to play a big part in the character selection process (obviously Sakurai wouldn't say this since he's a professional). These are inclusions that are all extremely viable for Nintendo, and would benefit Nintendo now and for the future. The list just looks very... calculated, if you know what I mean. This has nothing to do with Gematsu, I'm just saying be prepared for this to likely be the final roster (perhaps playable Dixie, too, since Nintendo be pushin' that 'more females' philosophy).
The way I see how the character selection process working for this Smash goes like this:
Relevant, popular characters,
&
Less-popular characters that are relevant and have the potential to popularize and expand.
But yeah, just a few thoughts of mine.