We see Jaime Lannister back in the Kingsguard armour, with of course the exception of the helmet he generally doesn't seem to wear anyway. He appears in a few different places in the trailer. He has a new haircut which could indicate that he's trying to get away from the flamboyance of his previous years, but the key scene we see him in is when he is looking at a new sword with Tywin in the background. This scene must be where Tywin gives Jaime the sword that will later be known as Oathbringer. The sword itself is one of two swords that were re-forged out of Eddard Stark's greatsword Ice. You know us fans, we love a sword with a name, and now we have two. The sword doesn't stay with Jaime for that long, as he takes it as an affront from his father since Jaime has had his sword hand chopped off. So the appearance of Oathbringer also means that we will be seeing Brienne of Tarth pretty quickly. Jaime gives Oathbringer to Brienne to use to go and track down Sansa Stark, who went missing before they returned to King's Landing. She names the sword Oathbringer as a reference to the promise she made to the since deceased Catelyn Stark, although circumstances result in her coming face to face with Catelyn before long.