Beta-tested Sun and Moon with the team for Pokémon France and I'm here to answer your questions ONLY related to new Pokémon through drawing from what I can remember. I won't be giving any information regarding the story progress or main plot. Also, the Sun and Moon demo is presumably to be released on October 18.

>Starters have exclusive Sun and Moon final evolutions. The leaked starter evolutions are Moon exclusive and are more based on human classes, while the Sun evolutions are based on regular animals.
Sun:
Popplio2 - Water/Fighting
Popplio3 - Water/Fighting
Litten2 - Fire
Litten3 - Fire/Poison
Rowlet3 - Grass
Rowlet3 - Grass/Ground

Moon:
Popplio2 - Water
Popplio3 - Water/Psychic
Litten2 - Fire
Litten3 - Fire/Dark
Rowlet3 - Grass/Flying
Rowlet3 - Grass/Flying

S'amuser!