OMG! That looks completely badass! Despite to some changes to JH's origin and abilities (he doesn't supposed to have supernatural gifts those are just myths/rumors surrounding him due to his mystique and badassery as an excellent bounty hunter)
Director Jimmy Hayward explained that Jonah Hex himself may be larger than life, but more in the mythic sense than the actual superpowered one. "I think Jonah Hex, he's been shot so many times, the legend is he's got one foot in the grave and one foot here on Earth, and so we approach it by everybody else's version of who Jonah Hex is," Hayward continued. "At the beginning of the film, we bring out the John Albano (creator of the character and first Jonah Hex writer) quote, 'He's a hero to some, a villain to most, but where ever he goes, they speak his name in whispers.' So at the beginning of the film, he's a scarred bounty hunter, just a horrible guy, this murderous guy. You tear the layers off, you see that there's this normal guy in there, but he's kind of in purgatory until he settles the score."
http://scifiwire.com/2009/07/sdcc-clearing-up-the-supe.php
It sounds like he doesn't actually have a supernatural power. And we are told that in the beginning of the movie three old men are siting around a campfire telling mythical legends of Jonah Hex and in the trailer we hear one of the old men speaking of Hex having a power as a rumored legend saying "Some say he..". Jonah Hex being almost mythical with legends and rumors about him as a supernatural demon definitely harken back to the original comics written by John Albano. Jonah was almost a personification of the night and the outlaw's fears and own imaginations.
And having Turnbull burn the right side of Jonah Hex's face for the death of his son Jeb, rather than an Apache chief burning the right side of Jonah Hex's face for the death of the Apache chiefs son, weaves Hex's scared face into the films storyline with Turnbull and could work better within the film and serve to make things more personal between Hex and Turnbull. Most movie adaptions take some liberates with the source material. As long as they are differences that don't change the essence of the characters. As long as he's former Civil War Confederate Jonah Hex who's face was scared and is now a legendary bounty hunter, etc.