I've seen it in a wow.com realm forum post, but couldnt get a link to the mod or even its name :/
But i am 98% certain that it exists.
AFAIK the scripting interface won't be able to call the new functions, they will only be accessible via keybindings.
That was posted elsewhere by Tigerclaw if I'm not mistaken. (Due to security reasons)
I looked a bit into the UI & Macro forums and came upon this thread:
http://forums.worldofwarcraft.com/t...e-customization&t=436010&p=1&tmp=1#post436010