Java Edition 1.8

Snapshots are planned to begin this month.

General
Difficulty
 * Difficulty can be locked for each world.
 * This is so you don't open a world meant for easy difficulty (or higher) on peaceful difficulty by accident.
 * This also is to avoid temptation to change to an easier difficulty in hairy situations.

Adventure mode
 * Hitboxes of blocks appear in Adventure mode only if the block can be interacted with (chests, levers, etc.).

Commands
 * New command . It will be able to modify NBT data at a specific coordinate. The  will merge with the block at that position.
 * Usage format:
 * Capability to detect entities in the same fashion as blocks.

Gameplay
Enchanting
 * Has separated XP level requirement, XP level cost and resource cost. For example, an enchantment may have a XP level requirement of 13, that is it will only become available for enchanting after reaching 13 levels of experience, but it will only cost 2 XP levels and 2 golden ingots
 * Currently the only (known) resource is gold ingots.
 * Only one randomly chosen enchantment will be displayed in the tooltip.
 * This means that additional enchantments could still be applied, even if they aren't mentioned in the tooltip. For example, if it says "Sharpness" in the tooltip when enchanting a sword, you know the enchantment can't include Smite or Bane of Arthropods, since they are not compatible with each other. However it may still add Knockback or Fire Aspect.
 * Enchantments only cost 1-3 XP levels.
 * Each additional XP level adds a tier of enchantment.
 * The list of possible enchantments is not reset until you enchant an item
 * In multiplayer, the individual player will have to enchant an item in order for his/her own enchantment list to update.
 * Levels are harder to obtain.

Anvil
 * Anvils will be re-balanced to meet the new enchanting system.
 * Renaming costs only one level.
 * Repairing costs are "flattened" for all items.

Blocks and Items
Door
 * They are stackable up to 64
 * The crafting recipe for doors now gives 3 doors instead of one.

Granite
 * A pink-brown stone
 * Comes in two variants: "Raw"(like cobblestone) and "Smooth"

Bouncy Block
 * A "bouncy" block that resembles a slime.

Stone Variants
 * Jeb said that working with stone variants was on his list for 1.8.
 * This includes Granite.

Possibly Spruce Fence
 * Not comfirmed but if you look under the Bouncy Block in the picture, there seems to be a Spruce Fence type.