Minecraft version 1.2 (now 1.2.2) has been out for a few days now. You can get it by updating the game in the Minecraft launcher.
The video above shows the new update in action.
Patch 1.2 Notes:
- New jungle biome
- Added ocelots
- Added cats
- Added iron golems
- New AI for mobs
- Tame wolves can have puppies
- Villagers will have children if there is room in their village
- New map height limit (256 instead of 128)
- New items and blocks
- Doors have been updated so that double-doors work better with redstone
- Added rare drops for mobs
- Many other minor tweaks and fixes
- Minecraft launcher has been updated.