Concerning the graphic novel, they're just saying that they'll use cut scenes that look like a graphic novel, e.g. like the Dafoe picture above. And yes, he's talking about Myst.

"Eden will be a PC title, and while early in development is planned for a release within a year, potentially either on the Antichrist DVD or as a download."

What he's saying is just that they want to release it simultaneous with a special edition DVD release, not that the game is on the DVD.

Until they delete it:http://www.youtube.com/watch?v=jCc_S1goFU0&feature=channel_page&fmt=18