Insider Nikki Finke and her site Deadline Hollywood Daily has speculated about the possible casting for Thor.

She comments that there is a big push to cast Josh Hartnett as either Thor or the antagonist Loki; whether this turns out to be the case is questionable, especially considering Hartnett’s previous refusal to play Superman. There is also an equal force wanting a relatively unknown actor to play the role; other actors inline include brits Charlie Hunnam and Tom Hiddleston, Alexandar Skarsgard, Liam Hemsworth and Joel Kinnaman.

Meanwhile, quite surprisingly, Natalie Portman is the current top choice as the female lead. /Film speculate that this could be either of:

1. Amora the Enchantress, Thor’s Asgard love-interest and antagonist.
2. Sif, Thor’s wife who is also a Goddess in Asgard.
3. Jane Foster, Donald Blake’s nurse who eventually develops feelings for him, without knowing that Blake is Thor

Do you see Portman as a Goddess or Enchantress?

The Thor movie adaptation has been penned by screenwriter Mark Protosevich (I Am Legend, The Cell). In 2007, whilst on strike, he commented on his plans for Thor with the Daily Herald:

“I loved Thor! [...] He was my favorite comic book character when I was growing up. When I moved out to L.A. I sold a pretty substantial comic book collection to finance the trip. But I kept all my old Thors.”
[...] “It’s going to be like a super hero origin story, but not one about a human gaining super powers, but of a god realizing his true potential. It’s the story of a Old Testament god who becomes a new Testament god.”
It will be mythic, but also bear the unmistakable qualities of a Marvel movie, an epic fantasy adventure.
“I think it’s going to surprise a lot of people”

In December 2008, actor and director Kenneth Branagh was confirmed as the directing choice for the Thor movie (MTV):

“I am directing “Thor” or “The Mighty Thor’ as you might like to call it,” he said with a smile before clarifying what the title of the film will be. “I think it will be ‘Thor.’”
ortunity to hear from Branagh about what appealed to him about the project. So what’s the appeal of “Thor,” Kenneth? “To work on a story about one of the immortals, Gods, extraordinary beings, inter-dimensional creatures,” he enthused.

He continued excitedly, “There’s science fiction and science fact and fantasy all woven into one. It’s based on Norse legends which Marvel sort of raided in a brilliant way.”

When questioned about casting and the then rumors surrounding Kevin McKidd:

“There’s been lots of talk [about casting] — I sound like a politician — but we are too early at this stage. We’re getting the story and the visual effects together and all of that is very exciting. Someone sensational is going to play the part but it is early days.”

“It’s a chance to tell a big story on a big scale,” said Branagh. “It’s a human story right in the center of a big epic scenario.”

The current release date is set to May 20th 2011, originally brought forward from a June release.