Out after Portal 2.
Co-op zombie kill-em-up Left 4 Dead 2 will enjoy new downloadable content, Valve has announced but there’s a twist.
Cold Stream is an in the works community campaign created by modder Matthew Lourdelet. Valve is so impressed, it wants it finished and chucked into DLC. But it wants the L4D community’s help.
“The very first step in creating a new DLC is deciding on the larger goals and constraints for the DLC,” wrote Valve on the Left 4 Dead blog.