revealed this week's mutation of choice, and it's another round of Follow the Liter, in which only one character can carry a gas tank at the time, and they always spawn together (meaning that Infected know where the survivors are going to be). Should be a grindfest, but Valve thinks you'll like it -- they're bringing some old modes like this back to see if they can "take" a second time around.
And just for kicks, you Left 4 Dead fans can head past the break for a (NSFW due to language) fanmade mashup between Pixar's Toy Story (the original one!) and your favorite zombie headshot game. We won't ruin the surprise, but after what happens below, Woody's going to need some pills here.