Empire recently got to speak with X-Men Origins: Wolverine producer Lauren Shuler Donner, who revealed some interesting tidbits on a sequel, including the film's writer, Christopher McQuarrie.
"That's the furthest along of all the X-Men projects on the boil. It's actually the story we wanted to use for the first Wolverine film, but [Fox head honcho] Tom Rothman preferred to set the character up with an origin story first. This movie will really focus on the relationship between Wolverine and Mariko, the daughter of a Japanese crime lord, and what happens to him in Japan. We're very fortunate to have a story mostly outlined for us [from the comic book arc co-written by Chris Claremont and Frank Miller]. And we wanted an A+ writer, so we want to Chris McQuarrie (Valkyrie, The Usual Suspects). He came in and has tightened the story and got really immersed in the whole thing - he's in Japan in his head!
We want to make it authentic so I think it's very likely we'll be shooting in Japan. Also, by the way, we are looking to have the Japanese Fox executives involved in helping and counselling us, because it's a different culture and we don't want to portray the way they speak, dress and act in an inaccurate way. I think it's likely the characters will speak English rather than Japanese with subtitles."