After less than 10 years in service Singapore Airlines is allowing their oldest A-380 leases to expire and is returning the aircraft to the leasing company. Singapore Airlines has elected to maintain their A-380 fleet at 19 aircraft siting the small number of routes the lumbering four engined aircraft is suitable for and the greater utility of smaller more efficient twin engined jets such as the Boeing 787 or the Airbus A-350. They will continue taking delivery of newly manufactured A-380s and park their "older" airplanes. 10 years is still very young as aircraft go with the average airliner serving 30 years or more depending on the number of cycles on the airframe.
The future of these retired aircraft and the continuation of the A-380 program as a whole is uncertain as there is very little demand for additional airframes given the small number of airports capable of accepting the behemoth and the higher operating and maintenance cost compared to smaller twin engined airplanes.