Sweeping changes have been made to villagers in patch 1.2. They have not yet reached their original design but, the new changes have created a much more organic interaction.
The villagers AI have undergone a substantial upgrade. Villagers will now interact with each other as well as interact with some passive mobs.
Villagers will now search out homes within the village and will go inside and seek shelter from the rain or during night.V They have also gained some survival technique and will flee from zombies seeking shelter in the village structures. Zombies will continue to pursue villagers and if the game is set to hard mode they will break down wooden doors and kill all the villagers inside.
The most important addition to villagers is their ability to mate. The mating of villagers is the only way to spawn an iron golem in survival mode. Villagers will mate without any direct interaction with the player but do require certain criteria to be met first.
For villagers to mate there must be available houses in the village. A house is defined as a wooden door that has an inside and access to the outside. Only wooden doors count toward mating villagers. Iron doors and trap doors will not promote villager mating.
The inside of a house is determined by whether or not the door is within five blocks of a roof. For a roof to be valid it top must be exposed to the outside and its bottom must be part of an enclose structure.
Villagers mate in a near 1/3 ratio (.35 is the exact number) meaning that for every three doors there can be one villager.
Because doors are used to indicate a house it is possible to create efficient structures with multiple doors to promote faster mating. Buildings like this are unsightly but can be used if the player is only interested in spawning a golem.
Edit: This post is for minecraft 1.1. MCedi tr1000 is what you need for minecraft 1.2. This 1.1 world generator mod is still useful as it generates epic landscapes that can be brought into minecraft 1.2. Check my newer post on how to bring your old 256-height levels into anvil format for 1.2.
I have recently become obsessed with the dessert biomes of minecraft. One of the things I’ve always wanted to do since I started minecraft, was to make a large sandstone temple. My heart sank every time I wish I could build something taller than 64 blocks high above the ground. Even after I found a height mod, I realized that the 256 height (bedrock to sky-limit) levels were not compatible with the standard editors MCedit and Word Edit. While it is fun to place every single block of large structures, editors help me get the project done faster so I can complete more of them and fix errors that would take days to correct without them. Fortunately, there is a version of MCedit which allows for editing large worlds.