yes. I think quite a few people have gone down this road at some point. I remember searching for ways to manipulate a virtual surface without changing it's flattened dimensions, and I never found what I needed.

I think the best solution would be to flatten the paper, scan it, trace the fold lines and determine which folds are "mountain" folds and which are "valley" folds. Then you could model the 2D folding diagram in grasshopper, and through trial and error, determine rules to create different geometries by manipulating the fold lines and points in 2D.

Or you could make a grasshopper definition that just looks like you folded something, but which requires you to cut each panel out and assemble it instead of folding the entire thing from a flat surface.

I know that your problem is not exactly the same, but the following discussion could help
http://www.grasshopper3d.com/forum/topics/origami-with-grasshopper

If you know the pattern on the paper, you can use Rigid Origami Simulator to get a 3D configuration in obj format.