Ohhhhhh soooo many things!!!
A thirst meter, Zebras, Lions, Crocodiles, PENGINS, Tiny Firefly's that you can catch and carry around like a lantern, Bunnies, Some peaceful mobs in the nether and more hostile ones, horses are able to eat the hay blocks when you place them down and it actually disperses like cake, more different kinds of villages, more randomly spawning structures with treasure, more CAKE!!! That's very important!, New ores, Emerald armour and weapons, Pearls that you can find under the sea... And that is all I want, Its not THAT much. Is it?