It's official. B.J. Penn signs on the dotted line to face Carlos Condit in a welterweight fight at UFC 137, which will likely receive second billing under the championship clash between Georges St. Pierre vs. Nick Diaz. UFC 137: "St. Pierre vs. Diaz" is scheduled to take place at the Mandalay Bay Events Center in Las Vegas, Nevada, on Sat., Oct. 29, 2011. To check out the latest UFC 137 fight card rumors click here.