The TAG Union Blog stated this:
To give a bit of history on Shadow: the movie was in development in 2011, when Mark Dindal was developing the feature from an idea by one J. Katzenberg. Mark started work on the picture in 2010.
I saw some of the early art and test animation, and it looked promising. Different. Mark was nice enough to sit down for a TAG blog interview when he was slammed with work on the film (we talked in a DWA conference room and cut the session short when he had to get to a meeting); seven months later he had departed the project due to creative differences. (From accounts these were actual, 24-karat creative differences. Not the fake press release kind designed to cover a firing.)
Alessandro Carloni, a DWA veteran, has been listed as director of Me and My Shoulder for some time. There was a long stretch where not much work was happening on Shadow; reamWorks staffers told me there was a skeleton crew and the word was out and about that the picture would most likely die a quiet death in its crib.
Now Film Divider and others say that’s not the case, and I hope it’s true.
Here is how Film Divider sees it:
In 2012, it was announced that Stanley the man, Stan the shadow and Heidi the woman, would be voiced by Josh Gad, Bill Hader and Kate Hudson respectively. It’s not clear if this will still be the case, though I’d think it’s more likely than not.
At the time, Gad posted updates about the film to his Instagram. Some are now deleted, but his copy of the shooting script is still there, and it features the above image on its cover;
Tom Hiddleston was later linked to the role of an evil shadow, the main antagonist of the film, though we’ve yet to confirm definitively.