The first poster for Prometheus, the prequel to Alien that nobody at Fox will admit is the prequel to Alien, is here and it's got a floating head. Of course that floating head is some kind of ancient alien statue, so I don't think it's something we can complain about.
The poster itself is rather mysterious, promising that the search for our beginning could lead to our end, which SPOILER seems to confirm reports that the plot is about meeting the aliens (the Space Jockeys?) who seeded life on Earth.
The space suited figure at the bottom of the poster is in a halo of light, and the way it's all composed really reminds me of the original Alien poster. On purpose, I'm sure.