Redstone Update

The Redstone Update is a planned major update labeled as 1.5. It was announced at MineCon 2012 at the Future Updates with the Minecraft PC Team and The Future of Mod API talks. It will probably be released sometime in January or February 2013.

Planned changes
Note: Most of the changes listed here have no detailed references since most of them were mentioned at MineCon, especially the Future Updates with the Minecraft PC Team and the The Future of Mod API talks.

You can watch the presentation here:

General
The features were:
 * Rewriting rendering engine
 * Will require a higher OpenGL feature-set
 * Will include some sort of fallback for older hardware
 * Support for high resolution textures
 * The internal layout of texture packs will change
 * Every block will have its own texture file
 * Supports the use of animated textures for all blocks
 * The geometry of individual textures can differ
 * Not intended to support HD skins
 * Much faster overall rendering, resulting in more frames per second (FPS).
 * Lighting fixes similar to the ones first introduced in snapshots 12w39a/b (during 1.4 development)
 * Support for fancy lighting control
 * Support for more realistic lighting, such as active furnaces only giving off light from their front surface
 * A new format for 1.5 texture packs

Gameplay

 * Redstone Improvements
 * More predictable and consistent redstone behavior
 * The functionality of BUDs may be affected
 * Eliminating directional quirks
 * Most of the timings of redstone contraptions will change
 * Overall redstone will be more like analog signals
 * Redstone signal strength will matter (for some blocks)
 * New ways of transporting items
 * Using minecarts similarly to Railcraft systems
 * New uses for storage minecarts
 * Better Inventory management
 * Holding down the left and right mouse buttons and dragging when holding an item now splits the items across the boxes you dragged over. Left button splits them equally across the boxes and leaves the remainder in your hand.  Right mouse button drops them one by one as you drag.
 * Double-clicking an item stacks as much of that item in your inventory as possible (up to a full stack) and picks it up without stacking any other loose stacks together.
 * Double-shift-clicking an item in a chest moves all of that item into your inventory neatly stacked into as few stacks as possible. The opposite is also true, moving all the items to the chest in as few stacks as possible.
 * Fix for many bugs
 * Fixed dropped anvil makes no sound when it breaks
 * Fixed linux users can't open to LAN because it's bound to 127.0.0.1
 * Some Redstone bug fixes
 * Fix for random black spots
 * Fix for some rendering bugs
 * Fixed TNT explosions being delayed until exiting and re-entering a world
 * Fixed rail duplication bug
 * Fixed tile entity crash bug
 * Fixed inventory crash
 * Fixed inventory mechanics breaking crafting
 * Fixed crash when TNT explosion destroys a chest
 * Fixed Hopper not picking up all items dropped into it
 * Fixed Cactus growing next to blocks

Blocks & Items

 * Redstone Comparator
 * It is the same as a repeater, but with 2 inputs
 * If input A is stronger or equal to input B, it either repeats the signal or outputs a fresh signal
 * Output is toggleable by right clicking.
 * If input A is weaker than input B, then there is no output.
 * Hopper
 * Places and takes out items in Hoppers, Chests, Furnaces, Minecart with Chests, Dispensers, and Brewing Stands.
 * Trapped Chest
 * Gives out a signal depending on the amount of players looking inside. 1 person = 1 strength signal, 2 people = 2, etc.
 * Crafted with a Chest and a Tripwire Hook.
 * Large Trapped Chests can be staggered with Large Chests to allow more compact storage.
 * Texture is slightly different than a normal chest, with a red stain around the latch.
 * Weighted Pressure Plate
 * Used to detect item entities
 * Gold version reaches full strength at 60 items.
 * Iron version reaches full strength at 600 items.
 * Linear, so 10 strength signal means twice as many items as a 5 strength signal.
 * Block of Redstone
 * Emits an on-state signal forever
 * Made with 9 Redstone Dust
 * Nether Quartz
 * Is a crafting ingredient
 * Daylight Sensor
 * Outputs a signal with a strength corresponding to the intensity of the sun
 * Nether Brick (item)
 * Obtained by smelting Netherrack
 * Crafting recipe is 2x2 Nether Bricks.
 * A Rail for Filling and emptying of storage minecarts
 * The possibility of linking minecarts together (driven by furnace minecarts)
 * Rails to unload mobs and perhaps players when reached

World Generation

 * Nether Quartz Ore
 * For encouraging the exploration in the Nether
 * Drops Nether Quartz