The trailer is full of shots of all out battle, suggesting that this season will see a real escalation of the battles we've seen in the past. With more and more armies coming into contact with each other and the promise of a giant throne winning war at the end of the final season, that escalation if inevitable. But who else, beyond the Greyjoys is at war here? You can see their flayed man standard emblazoned on their shields in some shots... The confirmation comes thanks to a familiar face, set against the background of the Bolton standard-bearing shields. And as further evidence, there's no greater hint of Wildlings than majestic facial hair and fabulous furs... So the wildlings did indeed heed the call to go and fight the Boltons at Winterfell. But without Stannis' forces to back them up how can they possibly hope to survive? Perhaps Ser Davos rallies Stannis' troops back to the front? Perhaps the Stark bannermen rally behind an alliance of the Wildlings and the Greyjoys? Time will tell.