You may need to exercise even *more* caution now with the pretty scary update, or your villagers won't reproduce after other villagers have "accidents." From the version history:

>After a villager dies to natural causes, excluding mobs, while a player is within 16 blocks or if a mob kills a villager, no baby villagers will be produced in the next few minutes ( http://www.minecraftwiki.net/wiki/Version_history#1.4.2 )

You may want to send less useful villagers to serve out the rest of their lives in iron golem farms, or you could create some "death rails" for sending villagers who have outlived their usefulness 20 blocks away from the village to "a place where accidents happen"