There is a new form for Necrozma,it will be inspired by a dragon or a pterodactyl,the type will be dragon/psychic.
The new form of Necrozma will be important for the story of Sun and Moon.
New evil team:Team Star.
New Ultraworld locations.
5 new Ultrabeast:UB-06 Embrion/UB-06 Illusion,UB-07 Anger,UB-08 Guardian/UB-08 Knight.
Lycanrock afternoon form will be maybe available,this form will be obtained only between 5pm and 6pm.
No new alolan form,no new Pokémon.
New areas,including cutted areas.
4 new Z-moves
Pokemon FS real name will be Pokémon Space or Pokémon Starlight.
It will be available for 3ds and New 3ds,it will be the last Pokémon available on this console.
And no,the Diamond and Pearl remake will not be available in this generation.