Displacement textures available in node editor

I think it would be nice to be able to access displacement textures as nodes, just like you can access Material, world, brush and even line textures as nodes.

At the moment, if you want to use the displacement modifier with a texture, you can only use a basic texture or an image. It is impossible to use the nodes editor for your displacement textures. The proposed modification would allow for a much more precise use of the displacement modifier in conjunctions with procedural textures.