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:
Working
Unity 2D of Ubuntu 11.04 (as using Metacity)
https://askubuntu.com/questions/44168/does-dragndrop-across-applications-while-switching-tasks-via-alt-tab-work-in-unxmonad on Kubuntu 11.04 (as of answer below, thanks)
Not working:
Unity (3D) of Ubuntu 11.04 (as using Compiz)
Drag and Drop across (fullscreen) applications, switching via Alt-TabUnity 2D of Ubuntu 11.10
Unity (3D) of Ubuntu 11.10
gnome-shell of Ubuntu 11.10