Two new posters have apparently been released, or leaked, for two of the campaigns from Left 4 Dead 2. The posters, published by the gaming site GNN, are for Campaigns 1 and 4 called Dead Center and Hard Rain, respectively.
Dead Center takes place in a shopping mall while Hard Rain takes place in a refinery. Valve has not confirmed the authenticity of the posters, but they certainly are interesting.
Check the external link to put your eyeball on the posters.