A new update for Fallout 3 is available. On Xbox 360, you will be prompted to update when you start up the game, while using your Xbox LIVE gamertag.

The update is in preparation for Broken Steel and also addresses some bugs too.

Here are the release notes.

Update 1.5 Notes (PC and Xbox 360)

New Features
New achievements for Broken Steel

Bug Fixes

• Fixed issue with VATS calculations not appearing properly for perks (PC)
  
• Fixed crash related to altered references between master files
  
• LOD objects render properly when loaded from DLC worldspaces
  
• Fixed issue with companion NPCs not loading into cells immediately after player

For those playing Point Lookout on Xbox 360, there is not an update to run the DLC. You only need the current 1.5 update.