The latest build of Minecraft, version 1.3, released today, giving crafters new items, functionalities, and gameplay changes. Moving right to the point, here's just some of the MASSIVE update brought to us, courtesy of minecraftwiki.net. Don't worry, the graphics are still nice and blocky.
* Single-player now runs a server internally
* Publish the single-player instance to LAN
* Automatically detect LAN worlds in multi-player screen
* Added trading with villagers
* Added emeralds, emerald blocks and emerald ore
* Added cocoa beans to jungles
* Added the Ender Chest
* Added tripwires
* Added new creative mode inventory with search functionality
* Made it possible to gain enchantment orbs from mining ore and smelting
* Added writeable books
* Added "large biomes" world type
* Added temples to jungles and deserts
* Added chat settings
* Added option to turn off and view snooper data
* Added more information on the debug screen (F3)
* New launcher with "Play Demo" button if not premium user
* Added /seed command to see map seed
* Added /defaultgamemode to set default game mode in a world (affects new players)
* Added /debug command for profiling
* Added SRV record lookup support
* Decreased max enchantment level from 50 to 30
* The /tp command can now send players to a specific coordinate
* Mobs can spawn on flat surfaces (such as up-side-down stairs)
* Updated language files
* Mobs are much less likely to glitch through blocks
* Server list can be reordered
* Nearby items in the world will auto-stack
* Stars are smaller and brighter
* Sky color in The End has been changed
* The "pick block" functionality has been improved
* Certain items that previously wasn't stackable can now be stacked
* Hill biomes are slightly taller
* Wooden log blocks can now be placed side-ways
* Wooden half-blocks now act as wood
* Water slowly drips through leaves during rain
* Minecarts and boats will be placed by dispensers, if possible
* Gravel texture has been modified
* Levers can be placed in the roof
* Creepers' explosions damage is now modified by difficulty
* Performance improvements
* And more...
For a full list, be sure to check out the wiki.