I have a dual-head setup (NVidia TwinView) where the second screen is an overhead projector. I would find it extremely useful if I could just drag windows using the Workspace Switcher between my screens. This would help a lot especially at times when the projector is blanked or switched off and I would like to move some windows to be projected when switched  on/unblanked.

For now windows can be dragged to different workspaces without altering they relative position (within workspace). What I propose is to make it possible to change the window position WITHIN the workspace by dragging it.
Changing window position could be implemented by dragging it with for example a modifier key.

Such a functionality is present ie. in the fvwm workspace switcher (whatever it's called).