Yes, it would really be great to have the displacement as part of the material system.
But IF thats not going to happen soon, how about the ability to at least transform (offset, scale, rotate) the displacement map from within the displacement modifier? That way it can match material's transforms.
I've included a couple of images to show an example of where its needed.
Thanks!
--Shift Studio.
p.s. if anyone has a work-around for the time being, please post it.