Vanilla is a product of Lussumo:
Documentation and Support.
The original directors of the films wrote the screenplay, and are the guys who did the Crank movies + Gamer. Not great movies by any stretch, but certainly entertaining action flicks. Jonah Hex is a largely action-oriented comic, and they were clearly fans, so really they weren't bad choices to direct the movie. Then, at some point early in development, they left due to 'creative differences'. This could mean nothing, but it's a red flag.
The next anyone heard of the movie, they brought on Jimmy Hayward as the director, a guy who's only previous credit is Horton Hears A Who. Again, could mean nothing, but another red flag. Since then Megan Fox has been cast, they've done a bunch of reshoots and some other shenanigans have gone on. Then the trailer comes out and consists almost entirely of poor dialogue and explosions. I had high hopes for the film once. At this point, it's a coin toss as to whether I go see it.
Oh, and Megan Fox isn't that hot.