According to ShockTillYouDrop Summit Entertainment (who has become a very popular studio due to the Twilight Saga) has acquired a spec script by Ben Magid -- who is currently working on the feature adaptation of the comic book Hack/Slash -- called Invasion, which is being described as a Cloverfield type style of film.
There isn't a lot to go off of right now regarding the story, but to get your imagination going the film starts with a wicked subway accident in Los Angeles in which the survivors (the film's protagonists) climb from the wreckage to find the, now snowy, city in ruins. What they encounter topside is bodies, mobs of people in a state of panic and acidic goo.
So let your imagination fill in the blanks until we hear more, but it has a good starting point.
Eli Roth and Eric Newman are producing the project. They have recently worked on the upcoming horror film Cotton.