Atlas Shrugged is one of my all time favorite books but, truth to be told, I don't think that Ayn Rand translates well to any other medium. In order to do the film justice AND get the story told in the average time alloted for a feature film, they will have to edit it so much that, at best, the story will be choppy and not be the same one that Ayn Rand wrote.
In addition, I don't believe that the mainstream theatergoers will "get it". There are no car chases, explosions, slo-mo blood and gore extravaganzas in the story to keep them glued to their seats. There is only a story that is too deep and intense to understand, not to mention Rand's philosophy.
What I suspect that Hollywood will do is make the film into a love triangle between Dagny, John Galt and Dagnar. That should have Ayn Rand spinning in her grave.
I would love to see the same design concepts used in "Sky Captain" or "Batman" (the first Tim Burton one) applied to "Atlas Shrugged". I think the looming, art deco style would be a perfect fit.