Believe it or not, ever since Katie Couric was a girl, she says she’s dreamed of becoming a hairstylist. Her fantasy will come true next week when she’ll give a haircut on-air. According to our spies at the Roy Teeluck Salon, tough-talking reality-star stylist Tabatha Coffey and a crew from Katie’s show commandeered the 57th Street salon for training, as Tabatha had Katie practice on a mannequin. While the lesson was taking place, Teeluck himself was prepping them for the Victoria’s Secret fashion show Wednesday.