The fire nation will attack anng and his friends at the western air temple. Look at the part in the trailer where katara, on appa ,is blocking fire nation airship attacks with a continous circle of water. The clouds are thick. Think back to the WAT there were many thick clouds. they were definitely attacking them. Or maybe they were headed to attack the NWT. Remember the fire nation couldnt defeat them on the ground. It would be different if there was an invasion from the air plus a ground invasion. what does anyone else think?