In the newest snapshot for 1.4, there is a 10% chance a zombie villager will spawn instead of a zombie.
Using a splash potion of weakness and then a golden apple on these zombie villagers will turn them into normal villagers.
Thus, you can start a village anywhere without having found a single village by simply building a house with at least 3x3 blocks of space inside, lighting it up, and of course giving it a door.
Then you just find some zombie villagers, let them follow you into the house, and heal them.
You then will have a village.
This is very good for people who are using large biomes or just can't find a village anywhere due to bad luck.
People complain about not having villages, and now they can have them.
This also stops griefers and zombie sieges from being able to kill off villages permanently.
Personally, I'm happy because I killed off a village in 1.2.5 not knowing that villagers had no drops or that they would have trading, so I can easily repopulate that village now.