Having the following issues in our large village since the Nether update:

1.  Villagers despawn much quicker than previously.  We had over 60 villagers prior to the update.  When the update happened in our realm we were down to 2.  We've built it back up to 30+ (by manually distributing food, replacing all the beds, etc.), but some randomly die / despawn despite being protected from mobs, having plenty of food, and enough beds / doors.

2.  Villagers don't adopt farmer profession.  We've had to manually distribute food as none of the villagers will convert to farmers despite having 5 medium-sized farms of different crops with several composters.  

3. Golems and cats are not spawning naturally based on the population as they were.  Golems that were user-created are wondering more slowly than previous, seem to despawn, and do not patrol the entire village despite unfriendly mobs being cleared from the village.