I'd imaging these would go blank in an emergency or at landing/takeoff. Can't imagine that reducing the terror factor for certain folks.
JAL had it, too, on ORD-NRT. A member of the crew would switch to different cameras, presumably based on what there was to see (front landing gear view during takeoff, just clouds straight down during most of the flight, etc...). I haven't flown JAL in close to a decade, so I can't say if its planes still have this.