The blog says the following about the concept art:
"For starters I must emphasize that not confirm the veracity of this news. But you may have some leaked concept art look of the Red Skull in the film of Captain America , which debuts next year. The style of conceptual art match those that leaked months ago of Captain America and Thor. Furthermore, the skull showed up holding the Cosmic Cube, which was confirmed in the film. However, there is no trace of actor Hugo Weaving in art." [Translated by Google Translate]Most concept art is done before casting, so its no surprise it doesn't look like the actor. What confirms these as legit is that they look exactly like the official movie costumes.
Captain America: The First Avenger is directed by Joe Johnston and stars Chris Evans. After being deemed unfit for military service, Steve Rogers volunteers for a top secret research project that turns him into Captain America, a superhero dedicated to defending America's ideals.
Via Mania and Splashpage