Hey,
Sure i think displacement mapping is something lux should have in the near future,
it's quite complex though and we need to stabilize the current codebase first before tackling issues like this.
I'd say this would be an excellent feature for implementation along with stuff like volumes, SSS etc after our v1.0 release

practically that would mean that we could start work on it from a development side in a couple of months,
but again this all depends on activity and stuff

Once v1.0 final is here we will be in a situation where we can start adding advanced stuff and unique features to lux easily,
as most of the foundation work will be done.
greetz,
radiance