In what appears to be a confirmation that Game of Thrones will use Malta for at least some King’s Landing exterior scenes, musician Wilko Johnson—cast as Ser Ilyn Payne, the royal executioner—will be filming there, according the Essex Echo and their discussion with his manager. It’s indicated that he had filmed for a week in September in the Belfast area, and there’ll be more shooting later this month in Malta. The article provides a great quote:
“He pulled his usual scary face on the set, but the director told him ‘you don’t need to do scary, you are scary’.”