Sure.  The new control has always been there.  I just noticed it now.

Select an object & edit its material.  Choose a mapping mode.  Add a layer & choose a mapping mode for the new layer.  On the top layer add a bump map and select displacement mapping.  On the 2nd layer add a bump map.  Now go back to the 1st layer and slide a 100% to the add to underlying layer bump slider.    That's it.

Here's a quick example: