It looks to me like it would be SO much cheaper for the park just to expand in the other directions. From the aerial photos, the biggest barrier appears to be World Drive.
Why not place new stuff around the park? The Hunchback Show is now empty. The ABC theater sits empty. I've even heard that Millionaire will close within the next 2 years. (from a Cast Member though.) Also, I heard the Indy ride from disneyland will be built out into the parking lot behind the stunt show.
I just dont see why they would expand over that road if theres more room in the other directions. Plus, as cheap as disney seems to be lately, I don't see them undertaking this kind of project, instead of simply replacing something else that exists. ex: the hunchback show