I saw an extended (13 minute) preview of Sanctum at International CES 2011 this year. I even walked away with a crappy Sanctum pen / light.
The movie itself is produced by James Cameron using the same 3D technology from Avatar. It looks like an interesting adventure, cave diving movie except the cave divers are using rebreathers. This movie will just reinforce the fact that cave diving is dangerous and should only be done with thousands of dollars in equipment!
I can’t wait to see this movie! http://sanctummovie.com/