Role-Playing World Record at PAX

Ars Technica is reporting that the people behind TerraDrive Live plan on setting a world record for the most participants in a role-playing game at this year's Penny Arcade Expo. This is the first I've heard of it:
Sometimes it seems like there is nothing new to discover in the world of gaming, which is why a project like TerraDrive Live is so exciting. Billing itself as the first "Massively Multiplayer Live Action Role Playing Game," or MMLARPG, the game will take place during the three days of the Penny Arcade Expo, and it has a lofty goal: inclusion in the Guiness Book of World Records for most participants in a role-playing game.