The FAA will regulate the infrastructure needed to support ETOPS operations and that will included expected stepped up maintenance and inspections to gain and maintain this certification.  Woe be any airline that cuts corners on this after being granted, because if they drop one in the ocean and kill a bunch of people, not only  will their operations in that region be at risk for suspension, but they will lose safety credibility.  Attorneys for the passengers will leave no stone unturned and if they discover insufficient or faulty maintenance contributed to the crash, the airline will pay through the teeth even more.