As a screenwriter on Conan The Barbarian, I get asked this question a lot.
The world of Hyboria, as Robert E. Howard described it, is fleshy and brutal. Bloody beheadings and bare-chested slave girls abound. However, while the movie is unflinching in its depiction of barbarism, slavery and warfare, the violence and nudity emerge from the fabric of the story. It isn't gratuitous.
Robert E. Howard's stories, although violent and perverse for their time, were not intrusively graphic either. So this is ultimately a movie about the character Conan, a character that will hopefully launch a healthy franchise of movies with stories and characters that celebrate Howard's work. Yes, you'll see blood and boobs, but this isn't a Cinemax movie; it's epic action/fantasy.
And yes, it's rated R.
Conan the Barbarian, directed by Marcus Nispel, hits 3D and 2D theaters on August 19. The film stars Jason Momoa, Rachel Nichols, Stephen Lang, Rose McGowan, Saïd Taghmaoui, Ron Perlman, Leo Howard, Steve O'Donnell, Raad Rawi, Nonso Anozie, Bob Sapp and Milton Welsh.