An update on the Left 4 Dead Blog announces the new Left 4 Dead 2 Update includes an encore of the Taannkk mutation. It also makes offhand mention of plans for an upcoming Midnight Riders DLC release, the first mention of this we can recall since a teaser website went live in late 2009. Here's word:

Midnight Riders?
The upcoming DLC is our experiment in not having a story tied to the DLC. While we are working on that, we also wanted to keep expanding the story and world of Left 4 Dead. We like comics, in fact we just released one yesterday for TeamFortress 2. So we were thinking about another comic. What about one starring the Midnight Riders? Vote in this week's in-game poll and let us know what you think.