Minecraft's snapshot 16w39c, otherwise known as the Exploration Update, has been released today and adds a whole load of new things as well as fixing minor bugs. The additions include:
"Added cursed enchantments
Added the Observer block
Added escape portals in The End
Added the Shulker Shell and Shulker Box
Added exploration maps
Added the Woodland Mansion
Added Illagers, and the Vex
Added Llamas
New command: /locate
Removed Herobrine"
Minor bug fixes include performance, textures, and a lot of other stuff which can be seen in the original post. Are you excited about these additions?