(Planned) Features Alright, so for planned features, I guess I should start by going through the blog post by Mojang. Please note that the original post may be paraphrased or changed in any way. Strikethroughs are not planned, normal text is planned, yellow text is in progress, small text is possibly planned.
New "Super Hostile" gamemode for a much more challenging experience.
Difficulty setting is now per-world.
New "ultra-realistic" graphics rendering setting.
New chase-style 3D camera perspective?
New hunger system for animals.
Overfeeding animals can have a negative effect.
New "Horse" mob with two different breeds.
Each animal has a gender and personality?
New rare breed of chicken called "Diamond Chicken":
Diamond Chicken may lay diamond or lapis instead of eggs.
Diamond Chicken may blow up from too much pressure. (most likely, will have something to do with Y-axis.)
New friendly Pink Wither, which is the complete opposite of the Wither.
Pink Wither shoots out Love, which works like bonemeal.
Having both a Pink Wither and a Wither in the world will cause a 200% increase in framerate.
All animals can be fed Golden Apples to unleash their hidden magical properties (see Magic section).
Chickens are now classified as a Monster.
Chickens can get upset from being looked at.
Attacking a lone chicken or Diamond Chicken will rarely summon additional chickens to its defense.
Fixed a bug causing Skeletons to miss their targets on occasion.
New Redstone Bug monster. (see Redstone section)
Furnaces have a new heat mechanic?
Heat needs to be regulated in Furnaces or they blow up?
Torches may burn out and may be relit with Flint and Steel?
New TNT slab called the Etho Slab.
New block similar to Droppers called Floppers.
Droppers were deemed too powerful.
Floppers turn everything that passes through them into raw fish.
Six (6) new decoration blocks:
(chiseled? brick?) Lapis lazuli blocks.
New compressed storage blocks for commonly mined ores:
Lapis lazuli block (block).
Redstone block block.
Lapis can be used for Lapis Furniture.
Added dyed glass.
Walking over many blocks can gradually wear them down.
Redstone (I may or may not include this):
Removed BUD behavior.
Actual Redstone Bugs added.
New Quantum Entangled Redstone made with 1 redstone, 1 diamond, and 3 lapis.
One QER will connect to another pair elsewhere.
QER may connect to other worlds.
Added BUD blocks.
New Magic and Luck levels per player.
Finding a rainbow after a rainstorm will be the primary way of obtaining Magic.
Finding a green-tinted Horse (or a Unicorn) will be the primary way of obtaining Luck.
New spell system added, costing Magic to perform a spell.
Spells can backfire depending on Luck.
New spells include:
Turn any item into fish.
Turn current biome into another biome.
Ability to switch gravity for another mob/player in the world.
Overhauled fishing mechanics.
New types of fish can be found in different biomes. (model?)
Fish can become scared if noise is made nearby.
New achievements added for fishing.
Extra items may drop when fishing, such as armor or maps.
Fish may occasionally flounder if they are held, reducing half a heart each time it "flounders".
Each animal/monster has different strengths or weaknesses.
World Generation / Terrain:
Many new mysterious adventuring locations.
6 new biomes.
New village building templates.
Flattened terrain slightly, with the exception of Extreme Hills biome.
Added floating sky islands.
Changelog: April 2, 2013: Started mod and created this post. Mod version 0.0.1.