"[We're going to] take Thor literally to other worlds," Feige told EW, "…[It will] primarily be the journey of that character, of he and Jane Foster and how the new dynamic with his father is working out, as well as what are the broader stakes for The Nine Worlds.”
The inclusion of Foster and Odin in the plot hints that Natalie Portman and Anthony Hopkins are likely to reprise their respective roles, but leading man Chris Hemsworth is, at the moment, the only fully confirmed cast member for the July 26, 2013 release.