Okay, so "True Blood" is not actually a feature film (it's the Alan Ball series on HBO), but the studio used this one-sheet as a prominent part of their publicity campaign. The series debuted in 2008, and the Megan Fox starrer "Jennifer's Body" comes to theaters later in 2009.
The posters are essentially dead ringers for one another, with the slight exception of one storytelling element: the "True Blood" poster features a subtle vampire fang, while "Jennifer's Body" has no such fang (since the film is about cannibalism, not vampires). But the similarities in overall composition, framing, color scheme, the heavy lipstick, tongue lick and blood drip are groanworthy.
Thanks to Alessandro for the tip!