We have actually developed an enhanced Media Manager component for the backend to do that, with copy/cut/paste/rename functions, as well as image manipulation (crop, resize). It's like a small Photoshop inside Joomla!
We've used it so far for our own projects, but hadn't had the time to release it to public. Perhaps we might schedule things and set a release date for April.
What do you think?
Below are a few screenshots to make you drool! Haha! :D
