A small entry on the Myst Movie site was posted today. They revealed that they are currently working on cutting down the length of the script.

"Most recently, the length of the script has come back to haunt us.  As a direct result of our last major project (presentation creation) we’ve been asked to cut the script down to a more acceptable length.  I’ve always been aware that this request would be made, I had just hoped it would be at a slightly later stage of the process.

Everyone on the team is frantically working to offer their input on the cuts.  We’re creating multiple versions between the six of us and then we’ll take what works from all of them and discard the rest."

Source: http://mystmovie.com