It seemed rather backwards that a movie called Snow White and the Huntsman would cast the Evil Queen before it found the title characters, but with Charlize Theron now higly likely to play the nefarious, apple-poisoning stepmother, the guys behind the movie obviously feel its time to fill the other major roles.
Variety reports that despite Tom Hardy and Johnny Depp both being rumoured for the part, Viggo Mortensen is now in talks to play the Huntsman. While that's a relatively small role in the original fairytale, this retelling beefs it up, so that the story becomes about the relationship between Snow White and the Huntsman, who's told to take the princess off into the wood to kill her, but instead teaches her survival skills so she can make it on her own (interestingly, there's been little mention of the dwarfs in any descriptions of the movie, so goodness knows how they fit in).
Premusing the talks bear fruit and Viggo does end up playing the Hunstman, that leaves open the question of who will be Snow White herself. The Variety report suggests Universal and director Rupert Sanders are looking for a relative unknown, in the same way as the Coens went for Hailee Steinfeld for True Grit. However Cinema Blend quote 'various sources' as saying that Kristen Stewart may play the role. To be honest though, due to her Twilight fame it was inevitable somebody would link her to the film at some point, and even Cinema Blend seem uncertain whether there's any validity to the idea, so at the moment this is merely a rumour, and a rather dubious one at that.
Snow White and the Huntsman is on the fast-track, with Universal planning a summer shoot and Christmas 2012 release, hoping to get it in cinemas before several other competing Snow White flicks, including one at Relativity that Tarsem Singh is attached to direct.