Since a lot of people seem to be curious or do not understand what 1.6.6 version means and such I've decided to compile an entire list of every item, mob and feature not included in this version of Minecraft so you can expect them later. If you want to be
surprised and such then do not read any further ahead.
◦New Textures for Cobblestone and Bricks
◦Mobs: Cave Spiders
◦Stone Bricks, Slabs and Stairs
◦Brick Slabs and Stairs
◦Creative Game Mode
◦Randomly Generated Structure system: Includes NPC Villages, Strongholds, Abandoned Mine Shafts and Ravines.
◦Deeper Ocean Biomes
◦Charge Bow Attacks
◦Melon and Pumpkin Seeds
◦Fleeing Passive Mobs when attacked
◦Unknown but upgraded sounds for Doors, Trapdoors, Experience Orbs, Chests, Fishing Poles, Bows, Fence Gates and Explosions.