If your looking for info on how DNN utilized the ClientAPI to accomplish drag n drop, this document covers the details.

My answer as to whether it can be done using the ClientAPI remains the same.  Yes.  Obviously the core already uses dockable containers.   However, I think your question is wheter or not you can write code to do this.  I cannot answer this.  All I can say is review the document I have provided above and determine for yourself if you have the skillset to utilize the ClientAPI for your purposes.

I readily admit that my purpose in adding DragNDrop into the core was more focused on using the ClientAPI to accomplish a specific goal (allow modules to be docked).  The document covers how that goal was accomplished.  The DragNDrop funcitonality is not broken out well enough to just plug into your own purposes.  This may be something I work on in the future.