I'm not saying that it wouldn't be great as a miniseries or some other type of show. I'm just saying that there are unique challenges involved in whatever they decide to do. Although Adrian and Patrick always had their hearts set on a big-budget Hollywood film.
I actually think most of the great storytelling in visual media is happening on TV and the web (and comics. Let's not forget comics). It's not so much in the theaters anymore (which is why I don't see that many movies, but watch lots of TV).
I can actually see Myst ending up as a Game of Thrones type adaptation. You have three seasons already set up with the books, and if you add in content from the games, and the ever elusive BoM, they you have at least 4 or 5 seasons right there. It wouldn't be a traditional structure, because you bounce around chronologically a bit, but it would be doable.
The one story that I want so be told is the story of the Ronay. The discovery of the Art, and the eventual evacuation of Garternay, and then establishment on Earth. I personally, think this was an excellent place to start (at least story-wise) for any Myst adaptation. It's only issue is it's so far removed from Myst the game.