It was automatic with a new itinerary given to me at the departure gate at JFK. The rebooked flights were with AA so I had to physically collect the new e-ticket and boarding passes from the AA Admirals Club in PHX as they could not be issued by USAirways. The ladies in the AA Club in JFK had been checking regularly with the USAirways gate staff about the flight status and rebooking process, I think this 'encouraged' them to find me a reasonable alternative.