Just the Noblity seems to be Unicorns or Unicorns with wings.
Princess Celestia and Princess Luna (All hail Luna!) are both winged Unicorns. Then you have Queen Chrysalis, King Sombra thought both of them were evil they both had horns.
Then you have Fancypants who Rarity describes him as the most important pony in Canterlot. He's basically a Wealthy center of social life in Canterlot.
Prince Blueblood who turns out to be a self obsessed snob.
Oh lets not forget the Wedding couple! Shining Armor and Princess Cadance.
So by the cast ... Royalty are all Unicorns or Winged Unicorns.
Commoners are Earth or Pegasus ponies.
.... Um... no really I'm not a Bronie I swear! QUICK someone fire Pinky Pie's Party Canon! I need a distraction!
