Tried testing out of curiousity and they don't work at this time. In my case I'm using Blender 2.76b. Path object is beveled (so that it would render - at least in Blender) and controlled by hooks attached to animated empties. The test I made is fairly simple, it wraps over into an overhand knot. (Was thinking it might be neat to do a series of full 3D knot ties in action.)
There should be two objects, but only one is visible. The second model (which is visible) in the upload is a mesh-conversion of the final overhand. Non-animated in this case.
Also any good work-around suggestions if support for use of paths like this isn't planned?