"Attach to target legend. Attached legend gets +4 hit points and can defend any of your zones."
For Cataclysm multiplayer, an attack on a fulcrum is considered and attack on your battlefield ZONE. So by extension, wouldn't the legend with this attachment be able to defend the fulcrum in his battlefield? I sure hope so, because I'm making a Helborg deck for my friend for the next game night and legends are hard enough to field as it is in Cataclysm...