Personally i wish all these posters were released simultaneously (Along with the ones at the Blu-ray preview thread - "Welcome to immortality" and Noomi with the hammerpede). Not just the big head. Imagine all these strange images around movie theaters with the title Prometheus - would really get people wondering what the film is.
Strangely enough, when I first heard of the "Alien prequel" title rumoring to be Paradise, I thought it was stupid, but over time, its starting to grow on me. I think it would've worked well with that tagline about heaven/hell too.