USA Today reports that the FAA has issued a 296-page regulation update which will allow the newest generation of airplanes to fly virtually any route. Currently, airplanes must often fly indirect routes as part of safety measures that require them to be a certain distance from an emergency diversion airport at all times.
Over the years, improved aircraft have lengthened this distance. The FAA mandates a certain level of maintenance and safety in order to allow such operation, including a plan to take care of passengers and extinguish fires in the event of an emergency.
With long international routes a priority for airlines, the ability to fly them more directly is critical, and airlines will invest whatever money is required to bring their planes up to these standards.