Which desktop environments allow to drag'n'drop files/data across applications while task-switching using Alt-Tab (without the need to move mouse cursor to a specific UI element and/or wait for other UI elements to become active)?
To the best of my knowledge:
Unity 2D of Ubuntu 11.04 (as using Metacity)
Does Drag'n'Drop across applications while switching tasks via Alt-Tab work in Unity 2D?
xmonad on Kubuntu 11.04 (as of answer below, thanks)
Unity (3D) of Ubuntu 11.04 (as using Compiz)
Drag and Drop across (fullscreen) applications, switching via Alt-Tab
Unity 2D of Ubuntu 11.10
Unity (3D) of Ubuntu 11.10
gnome-shell of Ubuntu 11.10