The domestic stuff isnt happening and shouldn't worry anyone. The international stuff is what should. Its what makes carriers money and its whats easily eroded with open skies and code share agreements.
Imagine a day where all domestic flying is carried out by contract regionals, connecting to hubs where all international flying is carried out by cheap no-name third world codeshare partners. The majors would cease to have any airplanes of their own and would be nothing but a middle-man organizing it all, creating the agreements, overseeing everything, selling the tickets, and skimming their chunk of the profit.
Its already happening. You can buy a plane ticket on United Airlines from the middle of nowhere of the Midwest US to the middle of nowhere eastern Europe... and proceed to fly thousands of miles through multiple airports and countries without ever stepping foot on a United airplane or ever being flown by a United pilot.