I'm kind of surprised that this isn't more commonly done already, given that fluid simulation is now readily available. Maybe that just proves how little I understand about the subject. :) I imagine that some sort of particle system would be a good starting point, to overcome the initial hurdle of not having a solid object to work with. Ron Fedkiw is using tetrahedral (ie quasi-solid) meshes in at least some of his research. Then it would need a physics simulation which made the particles stick together in the right way until struck. My guess is that you won't have to wait as long as "a few" years.