»Everything you need to know for 1.9 Update!

Dual wielding! The most discussed part of this has been combat: more specifically, shields. But you can dual wield other things, too! Holding an item in your right hand that cannot be right clicked (tools) will let you use an item that can be right clicked (blocks, torch) in your offhand! You can't click both at the same time, and bows don't work in the offhand slot.

Shulkers! This new mob lives in ender cities found at the edges of the end. They have 15 hearts of health and, when closed, have an 80% damage reduction. They deal 2 hearts of damage with projectiles and will give you the levitation effect, making you float! This can be bad as you can die from the fall damage.

Mobs! With commands, you can now make mobs glow and give them armor! You can also summon zombie villagers that will turn into a specific profession (blacksmith, farmer, etc) when cured! This will help alot when making adventure maps.

The end! The end now has the main body plus islands about a thousand blocks away. On these islands there are end cities and end ships. End cities have chests and will spawn shulkers. End ships will have shulkers, a hopper, a brewing stand, iron, random loot and a dragon head which you can wear! You can use these cool new portals to get to the islands, but have to ride a pig, boat, minecart, or enderpearl to use since its a 1 block gap. Chorus trees and plants are the new ender decor.

Arrows! You can now poison, heal, or damage mobs with the new tipped arrows! Mojang have added 15 new arrows with all sorts of affects.

Beetroot! New food which can spawns in villages, gives 1 hunger bar when eaten. 6 of them + bowl = beetroot stew which, when eaten, can restore 6 hunger bars.

New Potions!!! The ender dragon will now shoot dragon's breath, which can be collected with empty bottles! Used as a lingering potion, which can be any potion now! Basically, when thrown, lingering potions have a certain part of ground where, when walked through, they give the effect. Dragon's breath is the same as lingering damage.

Combat: Shields are the same as blocking with swords. They reduce damage but also lose durability. They are made with three wool down the left-most column, three planks down the right-most column, and an iron ingot in the middle. They can't be enchanted, but you can add unbreaking III using an anvil. Swords now have faster attack speed (1.45) and axes are slower (0.9). Picks have a tiny increase, and shovels are not updated. Haste/mining fatigue now effects pvp. Axes are slightly stronger, swords are slightly weaker. Hitting a shield with an axe has a 25% chance of disabling it. Swords can do a sweep attack, hitting multiple mobs.

Chickens can be bred with any type of seed, and pigs like potatoes.

Thanks for reading, there are much, much more updates so if you want to know, just ask. Any questions you have, just ask me and I will give you the answer.

*Edit*
Also, Mojang have added an elytra which lets you glide through the sky. This can only be found in dungeons or the end.
And, Enchanted Golden apples cannot be crafted .
Plus, there can be up to 128 strongholds in a world which is great!

 

More: The super secret settings button has been removed, enchanted golden apples are now uncraftable, skeleton trap horses and elytra have been added, and now there are a maximum of 128 strongholds. Also, loot tables and attributes are introduced.