It's called Daybreakers, and from the looks of the trailer, it has some real potential. The basic premise is that most of the people in the world have been turned into vampires, and the few remaining humans are farmed for blood. You can go into a store and buy a pint just like you would pick up a snack at a convenience store. The problem is that there aren't enough humans left to sustain the vampire population, so they start to look around for alternatives.
The first half of the trailer looks very promising, then the second half is the standard action movie montage. I'm hoping the movie will turn out to be like the first half.