Ser Davos is also heard in the trailer warning against inter-house squabbling: "If we don't put aside our enmities and band together we will die and then it doesn't matter whose skeleton sits on the Iron Throne."
Is he warning Jon and Littlefinger? Or Jon and Daenerys? Jon and Cersei? It's nearly impossible to say, since we're sure all three of those royal camps are going to come into contact this season.