Left 4 Dead 2 isn't dead yet. As promised, the Cold Stream update is finally coming to Xbox 360--and soon. It will hit tomorrow on Xbox Live Marketplace.
The release was confirmed with a tweet (via CVG). As previously reported, the community campaign will be released as a free title update, and adds a fight against zombies while trying to avoid rushing water. It also allows you to play with all Mutations all the time, but the Xbox 360 version requires the Passing DLC for that feature.