If it's crap ... We'll tell you
There are certain things that a filmmaker should have to do in order to truly consider themselves truly "successful"; one of which should be having Drew Struzan to create their poster. In a theatrical landscape filled with bad photoshops, text-over-face images, and all manner of poor design choices, having a traditionally illustrated movie poster by a living legend like Struzan is a rare thing (unless you're Harrison Ford, who seems to be in half of Struzan's work). Unlike the recent 'Super 8' poster (which was confirmed to not be his work), this poster for Paramount Pictures' 'Cowboys & Aliens' is 100% pure Drew:
Beyond his iconic pencil style and sketched shading, you can also tell it's by Struzan by the attention to detail and color scheme (having his name signed on the side doesn't hurt either). While it's still unconfirmed whether Universal will be using this artwork (they may use it for a poster, or inside an "art of" book, or any number of promotional items), I think it's safe to say that we would much rather have this as the official poster than the double-cliché "over the shoulder, blue and orange" poster they've been using.