Time for the snapshot of week 3, 2012! List of changes, since 1.1 last week:

• Ladders regained their collision box, and vines are climbable when they have a solid block behind them
• Added jungle biome (requires a new world) with new tree and leaf types
• Updated language files
• Dispensers will place mobs instead of releasing the spawner egg
• Zombies have new path-finding AI
• Wolves have new AI and can be bred (when tame)
  

Get the snapshot here:

• Client: http://assets.minecraft.net/12w03a/minecraft.jar
• Server: http://assets.minecraft.net/12w03a/minecraft_server.jar