Daiku >> Thanks. I never noticed that option before.
Matt666 >> Thanks for pointing the script out, I didn't realize what it actually did. (I changed the menu name in my copy).
ThomThom, if Rick wouldn't mind perhaps an "Eyedropper" version could be developed that works similar to the Materials Editor dialog:
a) You make your selection, right-click, choose "pick a replacement component", an eyedropper appears, click on another component (if you hover over another component without clicking then that component's name appears next to the eyedropper or perhaps a thumbnail) and the selection is replaced.
b) If you don't have a selection, right-click on any entity, choose "pick a replacement component", eyedropper cursor appears, click on a component (if you hover over another component without clicking then that component's name appears next to the eyedropper or perhaps a thumbnail), cursor changes to a paint-bucket, "pour" the replacement component onto another component(s), press any key to end.
Perhaps replacing a component with a group or vise versa would be useful too? Toggle through the 3 modes (comp to comp, comp to group, or group to comp) via the Tab key.