Get the Minecraft 1.3 Prerelease today, take a look at Snapshot w27 and be featured on Mojang’s YouTube channel

If you've been patiently waiting for the next Minecraft update, today is your lucky day! While the update doesn't officially release until August 1, you can download the Prerelease starting today.

You can also have the chance to be featured on Mojang's YouTube channel, by creating a 30 second video which showcases features from the 1.3 update. That's pretty exciting stuff!

Here’s a brief collection of all the changes made since Minecraft 1.2.5:

• The game now runs an internal server in single-player mode
• The single-player server can be shared on LAN, with LAN server detection
• Made it possible to use client-side commands by enabling cheats (this is defaulted as disabled for old worlds)
• Added an optional “bonus chest” to get started quicker
• It’s now possible to trade with villagers. Added emeralds as a currency
• You gain enchantment orbs from other tasks than just destroying monsters. Max enchantment level has been decreased to 30
• Servers can automatically suggest and distribute texture packs
• Added new world map elements (does not need a new map, but they’ll only appear in new areas)
• Added cocoa beans
• Added an Ender chest
• Added tripwire
• Stairs and levers can be placed up-side-down
• Wooden logs can be placed sideways
• More detailed change log here

You can download the Prerelease here:

• Client
• Server

Snapshot 12w27a

• Bug fixes!
• Optimizations!
• Please check your piston contraptions. Most we’ve tested still work fine, but some require changes to repeater delays and similar. Overall, pistons should have fewer bugs, but will appear to update slightly slower.

Also taken from Jens' post on the official site, here is some more detailed information about the update:

Minecraft 1.3: The Good

Lots and lots of bug fixes and new features. Players who mainly play in multi-player on servers should enjoy a smoother and more stable experience, as this has been our focus of the development. We’ve looked over the network packets and added encryption to prevent session stealing. Dinnerbone has updated the chatting screen, to allow for easier editing and clickable links.

The single/multi-player merge has added the possibility to share your single-player worlds with friends who are on the same local network. It has also enabled players to use multi-player-like commands in single-player (such as /gamemode and /give), but only if cheats are enabled.

We’ve added emeralds, emerald ore and a trading system that makes it possible to buy items from villagers. Villagers will add and remove items depending on what you buy.

We’ve added the possibility write in books and leave stories for other people.

We’ve added new terrain features, and you can choose to begin the game with a “bonus chest,” to get you started quicker.

We’ve added tripwire, so you can create new traps and contraptions.

We’ve also added new stairs, new half-slabs, cocoa plants and tweaked dispensers, leaves, cauldrons, levers, gravel, pressure plates, cookies, buckets, boats, minecarts, ice, furnaces… Plus you get magic orbs from mining and smelting (and not just killing monsters)!

Minecraft 1.3: The Bad

Since single-player has been turned into a shell on top of a background server, the game’s resource requirements have increased. When playing single-player, the game needs to be able to both simulate and emulate the world, which take many more CPU cycles. We’re working on optimizing rendering, but those improvements will not be included until Minecraft 1.4.

Minecraft 1.3: The Ugly

A couple of problems and expected features have been pushed to Minecraft 1.4. The most notable problem is the lighting issues causing black regions in the terrain. We’re looking into ways to solve this, but lighting is a very expensive calculation and we are struggling with finding a solution that doesn’t hurt framerate.

And the most notable missing feature is the modding API. Throwing out single-player was the first step in order to make the API possible, and that’s done now. We decided to release 1.3 without the API, because otherwise it would be an even longer wait for a Minecraft update.

We’ve also added an extremely basic version of “adventure mode.” We’ll work more on this in future updates.

[Mojang]