The Passing will cost 560 Microsoft Points ($7) on Xbox 360--the same price as the Left 4 Dead 'Crash Course' DLC--Valve apparently told the show, while we presume that, in true Valve style, PC users will once again receive the update for free.
The Passing sees Left 4 Dead 2's survivors meeting up with the original Left 4 Dead cast--three of them, anyway. New golf club and M60 weapons will be added as well as multiple new game modes, a new 'Fallen Survivor' special infected and a 'Witch Bride.'
"A month or so" after the release of The Passing, new Left 4 Dead DLC will tell of Bill, Francis, Louis and Zoey's journey towards meeting up with Coach and the gang--no doubt explaining why only three of them are present. We predict a tear-jerker.