The world as we know it will be changed, not gone. Eorzea will still be intact, just different. From a gamer's standpoint though, yes the world of 1.X is gone and 2.0 is a different world.
No one would use airships. If you can teleport to the city instantly, why would you use the airship which costs gil and takes longer? Chocobos would be needed still but how useful they are would be severely lessened.
