Don't get your hopes up. Seperating the picture in Predator into several layers will or should be a pain in the ass. It's not a case of making a building stand out in 3D, which has one straight concise wall with right angles, it's a case of thousands of leaves and other asymmetric vegetation. That's a lot of work.
It's not a question of whether or not it can be done - Jurassic Park proved that it can (e.g. raptors in the jungle scenes), it's a question of whether or not they half assed it.