And maybe they'll come up with someone totally unexpected like Downey Jr. as Tony Stark.
That casting choice was regarded as.. bold by many but when we saw the first pictures, saw him in the first scenes and in finally in the movie it became apparent as a brilliant choice.
Now the character is forever linked to Downey and i hope the same happens with Thor.
One possibility however may be that they are looking for two actors actually.. Dr. Donald Blake for one where Craig, McKidd or someone else would fit perfectly as Thor's human side and then someone with the physique to play a norse god.
One actor to play both may prove very tricky to find because they either lack the physique or the acting chops to play both.
About the only one i can think of currently would indeed be Brad Pitt in his Troy state but he may be outside the budget for the project and maybe even a too big name for the movie.. easily becoming a Brad Pitt movie accidentally labeled Thor rather than Thor with a known but not AA+ level actor.