I'd like to see a Drag And Drop manager functioning something like the AJAX manager.
You can select controls that can be draggable and then define drop targets for them.

Things it might include:
* Constrained movement, either X, or Y or within a boundary.
* Init distance.  Eg. you have to drag an object 20px to start moving it.
* Drag handle.
* Snap. to grid, or elements