UFC welterweight champion Georges St-Pierre stopped by the "UFC Tonight" studio and talked about the challenges he sees on the horizon. While everyone is clamoring for an Anderson Silva-Georges St-Pierre bout, he thinks there are still plenty of challenges for him to tackle at welterweight. And as he's claimed many times, St-Pierre said a move up to fight Silva at middleweight would have to be a permanent move because he doesn't want to cut back down. GSP also talked about his new book, his week of Hollywood glamor, and the reasoning behind that hair. Check it out.