Animated .GIF icons

It would be amazing if animated .gif files are accepted as an icon.
It is would be a simple addition, yet it would open up a world of new possibilities to make more interactive animated user interfaces.

It would be a Buch of fun too, Who does't want animated buttons!?

I know there is currently a way to get .gif files set as icons, But how great would it be if we can just drag gif's into the icon boxes.