41 new blocks and items were added to Minecraft 1.6 java edition.
Horse Update
The Horse Update unsurprisingly added horses, and carpets ... because horses need plush stables. Colored clay is added, but Mesa biomes won't be added until 1.7
Black Carpet
Black Terracotta
Block of Coal
Blue Carpet
Blue Terracotta
Brown Carpet
Brown Terracotta
Cyan Carpet
Cyan Terracotta
Diamond Horse Armor
Golden Horse Armor
Gray Carpet
Gray Terracotta
Green Carpet
Green Terracotta
Hay Bale
Iron Horse Armor
Lead
Light Blue Carpet
Light Blue Terracotta
Light Gray Carpet
Light Gray Terracotta
Lime Carpet
Lime Terracotta
Magenta Carpet
Magenta Terracotta
Name Tag
Orange Carpet
Orange Terracotta
Pink Carpet
Pink Terracotta
Purple Carpet
Purple Terracotta
Red Carpet
Red Terracotta
Terracotta
White Carpet
White Terracotta
Yellow Carpet
Yellow Terracotta
Attributes
Attack Damage
Horse Jump Strength
Knockback Resistance
Max Health
Mob Follow Range
Speed
Zombie Reinforcements
Effects
Absorption
Health Boost
Saturation
Potions Effects
Absorption
Health Boost
Saturation