I predict at some point the 'good guys' will hear Jon Snow's story about how he killed a White Walker, they'll cast the ******* king of the North aside, then having gathered all the Valyrian steel they can find will attack the White Walkers and they'll get massacred. It's at that time they'll all realize that Jon Snow is the rightful king of the Iron Throne, the child of prophecy, whose blood is mingled with ice and fire...the main ingredient the dragons need to drive Winter back beyond the Wall, and without him the Seven Kingdoms are doomed.