At Thomas Cook we have these on some A330 aircraft (the ex MyTravel ones) and one newer A320. A forward and downward facing camera is fitted and can be watched by the passengers on the seat back / overhead IFE (but the image itself is not available in the flight deck).
There is a button on the overhead panel to switch the cameras off.
It is a customer option when ordering the aircraft from Airbus. The system is called the "Landscape Camera":
The Landscape Camera system consists of two cameras installed forward of the nose landing gear. These cameras provide images to be shown on the Passenger entertainment system.....
....The cockpit crew can select the system off.