Something nice would be the ability to trigger any action from a macro, instead of just other macros.
Could be incredibly powerful in combination with batch files.
Winamp has a feature that lets you copy the path of the current track to the clipboard, so it would allow stuff like:
-Press hotkey to copy path to clipboard
-Launch batch file that reads the path in the clipboard and copies the file to a favourites directory
Or, alternatively, proper scripting in general.
Edit: Figured out a hacky way to do it, would be nice to have the ability to do this from the UI though