No, I did not copy and paste. I edited it so it would be more understandable. I just wanted to post what will be upcoming in 1.3! :D Feel free to discuss in the comments.

General
o Improved overall stability and performance o Reduced CPU, RAM & bandwidth usage

o Made Singleplayer internally use a Multiplayer server
o Added optional single-player commands called "Cheats" on non-hardcore worlds o Type / and then hit tab to autocomplete & get help on various commands
o Most commands from MP are available

o Added option to let LAN friends join SP games o You can choose which gamemode players join in and whether they are allowed to use cheats

o Added demo mode for non-premium users o Lasts 5 game days per world

o Added chat options o Change which parts of chat are shown and how opaque it is
o Toggle chat colors, links being clickable and warning prompts for links
o Option to rebind the command key, which opens the chat with / in the textfield

o Mobs can now spawn on top slabs and upside down stairs
o Improved F3 mode: o Truncated coordinates to 5 fractional digits
o Removed frame rendering time history graph (bottom-left)
o 3 new values: o ws: Walking speed (constant)
o fs: Flying speed (constant)
o g: Boolean value, true when you touch the ground

o Updated language files o Added tooltips for all types of Monster Egg blocks and the End Portal Frame
o Added more descriptive tooltips for different types of tree-related blocks, sandstone and stone bricks[4]
o Localized server commands
o Added missing commands-related strings
o Added missing double chest GUI caption

o Fixed many bugs o Fixed texture packs in folders not showing their icon and description
o Fixed Man-in-the-middle attack allowing hackers to log in as you when you visit their server
o Fixed the Open texturepack folder button not working on OS X

Gameplay
o Added Adventure mode[5] o Only playable using commands
o Building, setting things on fire and using buckets is disabled
o Players can only interact with mobs and the environment

o Added trading[6] o Using emerald as currency, villagers will, depending on profession, offer different trades to players
o There are three kinds of trades: Selling, buying and enchanting
o As displayed in the top-most part of the trading GUI, villagers take one or more items or item stacks and give back something
o After trading, villagers will sometimes emit purple particles for a few seconds to indicate that their trades changed
o Otherwise unobtainable bottles o' enchanting and chainmail armor can be obtained by trading

o Improved Creative mode inventory o There are categorized tabs for various groups of items and blocks
o Added a search tab which will automatically be switched to when the chat key is hit
o Added survival inventory tab, which shows the full inventory, a 'Destroy item' slot, armor slots including a preview of your character and a 2x2 crafting field
o Items can now be deleted from the inventory by shift-clicking them
o Added layered snow block, Monster Egg Blocks (Silverfish spawning blocks), Ender Portal frame and all potions[7]
o Now shows potion effects' timers like in Survival

o Improved experience collection o Depending on ore type, experience now drops from ores that drop items
o Taking smelted items out of furnaces gives experience now
o Destroying mob spawners gives experience now
o Adjusted experience level progression: o Levels 1-15 cost 17 XP points each
o Levels 16-30 cost 3 more XP points than the previous (cost = 17 + (level - 15) * 3)
o Levels 31-o cost 7 more XP points than the previous (cost = 62 + (level - 30) * 7)

o Improved enchanting o The new maximum level with bookshelves is 30, without 8
o 15 bookshelves are enough to reach level 30
o The 3rd slot shows the most expensive possible enchantment more often
o Increased chances for multiple enchantments at once
o Adjusted enchantments' to go with the new maximum level

o Added writing in books o New crafting recipe for books: 3 pieces of paper and one piece of leather in any possible shape
o New item: Book and Quill - Crafting recipe: 1 ink sac, 1 feather and 1 book in any possible shape
o Right-click to write on & edit up to 50 pages or read
o Click 'Done' to save the book, 'Sign' to choose a title and finalize the book

o Improved Multiplayer o Made entities less likely to glitch through blocks
o Added automagical downloading of standard sized texture packs when joining servers
o Made server commands more descriptive
o Added reason parameter to /ban
o Added /seed command to show the map seed
o Added /defaultgamemode command to choose the gamemode new players start in
o Added /debug command to enable and disable profiling
o /kick messages can now contain "n" to force a new line
o Blocks other players are mining now show cracks[8]
o /tp can now be used to teleport to specific coordinates
o Made server list re-orderable: shift+click or shift+arrow keys move selected servers
o Server list now scans for LAN servers
o Added hardcore difficulty: Players are banned upon death[9]

o Added many minor things o Individual, stackable items near each other on the ground now become one item stack
o Added shift clicking support to armor slots, brewing stands & enchantment tables
o Added setting to disable servers offering you texture packs
o Made the stars smaller and brighter[10]
o Villagers spawned from spawn eggs will get a random profession now
o Removed the downwards knockback while drowning
o Doors being broken by zombies now show their damage

o Improved the Pick Block key o You now get the actual block
o You can now pick paintings, boats, minecarts and mobs, which will give you their spawn eggs
o Picking huge mushroom blocks now gives mushrooms
o You can no longer pick portal blocks

o Fixed many bugs o Fixed glitchy mob prediction in multiplayer.[11]
o Fixed fishing lines not showing in SMP.[12][13]
o Fixed flying slowly in liquids
o Fixed blocks with the same id but different data/damage values stacking in Creative inventory
o Fixed boats & minecarts not being one-hit breakable in Creative
o Fixed raw fish, dyes, saddles, potions, milk buckets and tools depleting in Creative
o Fixed water destroying non-solid blocks when breaking them from above
o Fixed Silk touch giving you only one slab from double slabs
o Fixed redstone updates not propagating through unloaded chunks[14]
o Fixed arrows scooting up to the top of the block they were shot on in MP
o Fixed repeaters getting stuck when loading their chunk
o Fixed endermen not opening their jaws in MP
o Fixed tools taking damage when breaking insta-breakable blocks
o Fixed fully charged arrows not showing their particle effect in MP
o Fixed many sounds not playing in MP[15][16][12][17]
o Fixed magma cubes' and slimes' jumping animations not showing in MP
o Fixed thunderstorms not darkening the sky in MP
o Fixed weather not fading in or out in MP
o Fixed enchanted armor and tools not glowing to other players
o Fixed ender pearls and eyes of ender not being aligned in the inventory
o Fixed explosions not pushing players back in MP
o Fixed TNT not knocking back players in MP
o Fixed pistons not pushing back players in MP
o Fixed the arrow representing players on held maps being offset
o Fixed being able to duplicate sand, gravel and powered rail
o Fixed placing a piston in front of another powered, but not extended one resulting in a glitched piston with the head's texture on all sides
o Fixed TNT dropping as a ressource on creative mode
o Fixed powering specifically glitched pistons crashing the game
o Fixed players on minecarts, boats or pigs and spider jockeys not being displayed in the correct location

World Generation
o Made sub-biome type mountains like Desert Hills or Ice Mountains taller
o Made cocoa beans appear on some small jungle trees
o Added optional starting chest on non-hardcore worlds[3] o Contents: wooden & stone tools, bread, apples, logs, planks and sticks

o Added large biomes world type, increasing biome sizes immensely[4]
o Added desert-specific villages
o Added Desert Temples o Built out of various kinds of sandstone and wool
o Include hidden chest room and TNT trap, with loot including rotten flesh, bones, iron ingots and gold ingots, diamonds and emeralds

o Added Jungle Temples o Built out of various kinds of cobblestone
o Contain multiple tripwire traps triggering dispensers filled with arrows
o Loot chests include bones, rotten flesh, gold ingots, iron ingots, diamonds and emeralds

o Added emerald ore o Only generates in Extreme Hills biomes
o Occurs up to 8 times per chunk in veins of 1
o Generates between layers 4 and 31, inclusive

Blocks & Items
o Emerald Ore o Drops Emerald

o Emerald o Is used to trade with villagers

o Block of Emerald[18] o Crafted by putting 9 emeralds on a crafting table

o Ender Chest o Crafted by surrounding an eye of ender with 8 pieces of obsidian
o Stores each player's contents across dimensions and all Ender Chests
o Contents are preserved even if all Ender Chests are destroyed
o Explosion-resistant
o Emits light and purple particles
o Unless mined using a Silk Touch-enchanted pickaxe, they drop 8 obsidian[19]

o Tripwire Hook[20][21] o String in between needs to be placed manually[22]
o Breaking the string triggers a redstone signal, cutting it using shears doesn't
o Entities like boats, mobs, arrows or players touching the string trigger a redstone signal[23]
o String can be up to 40 blocks long[23]
o Crafting recipe: Iron ingot on top of a stick on top of a wooden plank

o String o Can now be placed on the ground decoratively

o Furnaces o Can be fueled by wooden tools now
o Return an empty bucket when using lava buckets as fuel now

o Ice o Instead of melting in the nether, it now disappears
o Can be obtained using Silk Touch-enchanted gear now[24]

o Glass Panes o Can be obtained using Silk Touch-enchanted gear now[25]

o Nether portal o Leaks into the Overworld now: Depending on difficulty, zombie pigmen rarely spawn in them

o Half slabs o Added all wood types
o Wooden slabs crafted after the update act like wood
o Will now be top slabs when placed on the upper half of a block's side
o When placed upside down, rails, pressure plates, levers, doors, torches, redstone torches, repeaters, redstone dust and beds can be placed on them - Redstone dust behaves like on glowstone - It transmits power horizontally and upwards, but not downwards. Redstone torches don't power redstone placed on slabs/stairs above them.

o Stairs o Added Sandstone Stairs
o Added wooden stairs for all kinds of wood
o Adjusted hitbox
o When placed upside down, rails, pressure plates, levers, doors, torches, redstone torches, repeaters, redstone dust and beds can be placed on them - Redstone dust behaves like on glowstone - It transmits power horizontally and upwards, but not downwards. Redstone torches don't power redstone placed on slabs/stairs above them.

o Leaves o Water slowly drips through them when it's raining

o Cauldrons o Slowly fill up when it's raining

o Dispensers o Minecarts & boats will now be placed if there's rails/water in place
o Instead of dispensing buckets, dispensers will now suck in or place water or lava in front of them

o Gravel o Changed texture

o Jungle leaves o Have a 1/200 chance to drop a cocoa bean when destroyed now

o Lever o Can be placed on the ceiling now

o Wooden pressure plates o Are triggered by arrows now

o Pistons o Changed a few things to fight bugs, which now causes them to appear to update slightly slower - some contraptions may require changes to signal timing

o Cocoa beans o Retextured item
o Can be planted & grown on jungle wood now
o Can be grown instantly using bone meal

o Cookies o Give a full hunger point now

o Nether Warts o Can now be grown in the Overworld and in the End

o Empty buckets o Stack up to 16 now[26][27]
o Stacked buckets work just like stacked glass bottles do

o Signs o Stack up to 16 now
o Crafting now gives 3 signs instead of 1

o Golden Apple[28] o Has two crafting recipes now, the new one replacing gold nuggets with gold blocks
o Second tier gives Regeneration IV, Resistance and Fire resistance effects
o Only second tier glows like enchanted tools
o Has attributes the Golden Apple had before 1.1[29]

o Spawners o Added NBT tags to further customize spawned mobs
o Only changeable using map editors or mods

o Boats o Are not broken by lilypads anymore, instead they run straight through the lilypad now, breaking and sometimes dropping it
o Are less glitchy and more responsive now
o Increased maximum speed
o When exiting, players will be moved from the boat
o When broken, they drop a boat now

o Minecarts o When on rails, they can be accelerated a bit while sitting in them
o When exiting, players will be moved from the minecart

Mobs
o Pigs o Drop 1-3 meat now

o Slimes o Reduced spawn rate in superflat maps

o Silverfish o When suffering from poison potions, they will now spawn more silverfish from nearby silverfish blocks more often

o All hostile mobs o Become aggressive towards the last mob or player that hit them now.

This was all copied from mincraft wiki if you would like to see it here:
http://www.minecraftwiki.net/wiki/Upcoming_features