Bukkit

• Requires a WorldEdit.jar either in the plugins directory or in the VirtualPack directory
  
• Configurable commands
  
• Multiworld support (World-based configuration, see the configuration page)
  
• Fixed permissions again
  
• Fixed book enchanting
  
• Minor bug fixes
  
• "/v a" is now "/v ad", the Anvil will be "/v a" later ;)

Read this: This version will rename both your config.yml and lang.yml due to major changes. This means you will have to start your server, stop it, edit the config and start it again. And you might want to read the configuration page again.