Left 4 Dead 2 Taking a Last Stand

An update to the Left 4 Dead Blog reveals plans for The Last Stand, an upcoming community-led update for Left 4 Dead 2, the zombie sequel many thought Valve had left for dead. Here's a Teaser Trailer and here's what they have to say about this:
It has been many years since the infection first hit. Radio silence, no sign of life, nothing but lingering hopes... CEDA is not going to save us. But there is hope! A few brave souls have continued the fight against all odds, and soon we can all benefit from their resilience.
"The Last Stand" is an update for Left 4 Dead 2, created by the community, for the community. Additional details will be coming soon.