According to the show's website Stewart will be the first guest of the evening. Also the official website for the movie says that an exclusive clip from the movie will be revealed on the night.
"Welcome to the Rileys" also stars Jame Gandolfini and tells the story of a man on a business trip to New Orleans who seeks salvation by caring for a wayward young woman (Kristen Stewart).
This will be Stewart's first TV appearance since the beginning of the summer during "Twilight Saga: Eclipse" promotions. I bet all Twihards and Stewart fans will be waiting to hear from the horses mouth how her summer has been.