Arriving soon, is the new version for Minecraft PC! Minecraft 1.9, or the combat update! Here is all of the information of what will be added.
General
Animations/Entity models
Might include model changes within the NBT data.
Would be implemented via resource packs.
Will make better use of code so that map/mod makers can create better/new mobs.
Same as the block data changes in 1.8.
Captions/Subtitles
Subtitles which display for each sound for the hard of hearing/deaf.
An example would be “Creeper hissing”.
Would have < or > to point in the direction this sound is coming from.
Status effect UI
Displays status effect icons ordered by time left
Positive effects are on the top row, negative effects on the bottom row
Effects that are about to run out blink
Gameplay
Dominant hand option
An option for players to change their dominant hand on their player model
Dual wielding
Only the main hand can be used for attacking
Bows can be used even when something is in the other hand
The other hand is invisible in first person view when not holding something
Key to swap items between hands, default: F
If the item in the main hand doesn't have a right-click action, the other item will be used; Workaround for placing blocks while holding tools with right-click action
For example, if you have a pickaxe in your main hand and a torch in your other hand, right click places the torch.
The off-hand slot is displayed next to the hotbar, possibly on the off-hand side
Some attributes and enchantments will apply to the off-hand item, while others will not.
Levitation status effect
Recieved when player is hit by shulker projectile
Makes player float into the air
Blocks
New block type.
Grass Path
A 15/16 block tall grass-like “path”. It features a somewhat similar texture to the grass block.
Chorus plants
Tree/cactus-like arrangements of new purple block
Drop when supporting block is destroyed, like cacti
Drop edible chorus fruit items
Can be farmed by planting the chorus fruit flowers on top of the plants
Flowers don't drop when the supporting block is destroyed so you need to hand-pick them
New purple blocks
Derived from the chorus plant
A brick block with slabs and stairs and a chiseled brick block.
End stone bricks
Slabs and Stairs
White glowing pole blocks
Placable horizonally and vertically which produce white particles
Items
Chorus fruit
Obtained from chorus plants
Arrow
4 new arrow types.
The gold colored arrow is the spectral arrow,
Shows mob and player outlines in their team color when hit - even when invisible
NBT tag for entities to disable outlines
The glowing is a status effect - you can find out whether you're glowing from a spectral arrow using the status effect HUD
Green arrow is the poison arrow
Grey arrow is the invisibility arrow
Arrows can be tipped with potions which will be applied on hit
Each differently tipped arrow is available in the creative menu, just like enchanted books
Effect is applied on hit
Shields
Will be used for blocking instead of a sword.
Can be used to attack and defend at the same time.
Can use two shields at the same time
Shields can have customizable patterns, like banners
Used to block attacks from the side the shield is held on
World generation
End city dungeon
A new type of dungeon with new blocks and the shulker mob.
Generated structures
Added support to rotate and mirror structures.
End gateway portal
In order to access the portal, you must throw an enderpearl.
Used to access other islands after defeating the Ender dragon the first time.
Mobs
Shulker
Short for "Shell Lurker" (or shulk.. I'm really feeling it!)
It can hide in it's shell, making it appear as a block.
Appears in the End city dungeons
Opens up and shoots projectiles which only move along the x/y/z axis
Using commands, they can be made to be part of a team to attack other teams and can be used as defense mobs
Launch projectiles, which run across the X, Y, or Z axis, though they can change axis.
Projectiles can be knocked away by attacking them.
Getting hit by one causes damage and provides a levitation status effect which makes players travel upwards
Planned changes
General
Shaders
Switch away from using fixed-function OpenGL to using Shaders.
Removed/moved the Super Secret Settings and Broadcast Settings
Block models
Models can be put together based on BlockState attributes - As a result, the vanilla set of block models was reduced by almost 300 models
Gameplay
Bosses
Proper support for multiple bosses’ health bars, so they show at the same time without obstructing each other.
Clouds
New cloud rendering system.
Death messages
Death messages will now be displayed on the player's death screen as well as in the chat.
Inventory
Rearranged the survival inventory and the creative "survival tab" to accommodate the new shield slot.
Status effects
Now shows in the top right of the screen
Good effects on the top, bad effects on the bottom, left-most effects expire sooner
Effects that are about to run out will blink
Commands
/clone
Allows for mirroring/rotating structures
Blocks
Armor stands
Can now dual wield
Command blocks
Will have a new UI
Will contain tab to complete.
Ender crystals
A version of the ender crystal can be crafted which spawns another dragon when placed
Items
Bows
The bow in your hotbar now shows an arrow when being drawn.
Arrows in the off hand are prioritized over arrows in the rest of the inventory slots
Ender pearls
Can now be thrown in creative mode
Maps
Now display as a mini map when held in either hand, rather than being held with both hands.
Swords
Can no longer be used for blocking.
World generation
End island
A set amount of differently-sized pillars are arranged in a circular fashion
The tallest pillars have iron bars around their ender crystal
The exit portal is pre-generated, but without the dragon egg and portal blocks
Infinite number of islands in the end
Mobs
Ender dragon
Revamped boss fight inspired by the Console Edition.
The dragon can be respawned as often as you want by placing player-made craftable ender crystals
The dragon breathes fire/purple particles on players and mobs
The dragon will defend the obsidian pillars more the further the fight progresses
Every dragon drops dragon breath, but only one dragon egg can be obtained
Hostile mobs
Will now have animations to show that they are attacking.
Can dual wield.
Skeletons
Will have animated arms and bows.
Act a bit more like the player.
Arms are normally down, but they will bring them up to aim when aggravated.
They now have the same drawing animation as the player, indicating when they are going to attack and with how much force.
More different textures for mobs
FEATURES MENTIONED IN AN INTERVIEW WITH DINNERBONE:
Sounds for when you blocked an attack
Positional damage blocking with shields is not implemented yet
Potion arrows balancing will be done after snapshots start
Player-spawned dragons don't drop as much XP as the first one
The end gateway appears after killing the dragon
Ender pearls throwable in creative mode might not be kept
The additional end islands are arranged in a circular fashion around the main end island, like a donut (with quite some distance), after using the end gateway you end up in the direction you aimed at
Chorus plants grow in stages and can be planted in any dimension as long as it's on endstone
Snapshot unlikely to be released within 2 weeks
Mapmakers can make skeletons shoot potion arrows
I am hyped for 1.9!