Valve have now stated that the delayed DLC expansion for Left 4 Dead 2, called The Passing, will be released this week - costing 560 points on Xbox Live and €7 on PC. The pack will feature a brand new chapter in the zombie saga, where the gang from the first Left 4 Dead will appear. There will of course also be new weapons and some new special zombies.
Valve haven't said exactly when the expansion will be released, but promised that new information will be coming to their L4D blog over the next couple of days.