Kevin Feige, President of Production at Marvel Studios, told Empire some updates regarding the adaptation of Thor and Avengers. First, he talked about Thor:
We will probably be having cast announcements in the next month or so on Thor. We're looking to cast Loki and Odin soon, and the main female role. And we'll also hopefully have lockdown shortly, gearing towards the beginning of production, which will be early next year. So I think there will be a lot of announcements between now and then.
Director Kenneth Branagh has already confirmed that shooting was to begin in January of next year. As for casting rumors, Josh Hartnett has been mentioned as the front-runner for Loki, and Natalie Portman the female lead, likely Thor's wife Sif. Looks like fans will know for sure sometime next month.
Feige also updated Branagh's pre-production:
Branagh's here, we're prepping, and he's put together some spectacular animatics already for our first action scene. We're digging into the second and third now, and we are just embarking on a rewrite of the draft.
As for The Avengers:
Zak Penn [X2: X-Men United and The Incredible Hulk writer] is already on board The Avengers [as screenwriter] and he's spending a lot of his time looking into what we're doing with Iron Man [2], Thor and
Captain America, seeing how we're tying it all together. And he's beginning to outline the script now -- he'll be doing that over the summer.
Feige offered no update as to whether Jon Favreau will direct The Avengers. Thor opens June 17, 2011, while The Avengers opens May 4, 2012.