Posted this in the PvP forums, but it looks like the Carteneau Flats zone is Frontlines.

These are two shots of Frontlines they showed us previously;




Compare with this;



If you watch the first few seconds of the trailer, the zone is very similar, not to mention there is a group standing over a group of dead players (so, PvP), and a large group of players riding to a large location all on Maelstrom Chocobos (so Team Maelstrom). The tower in the background is virtually identical to the tower at the Twin Adder camp from the previous image.