Penny Arcade today announced that pre-registration for the Penny Arcade Expo (PAX) event from Washington - August 25th-27th - has been extended to August 3rd. Exhibitors include, but are not limited to, Microsoft, Nintendo, Nvidia, ArenaNet, America's Army, Turbine, NCSoft, Ubisoft, Mythic, Sabertooth Games, Foundation 9, Rockstar, Flying Lab, Creative Labs, The Behemoth, Garage Games and Red Octane.