I wouldn't be so certain about that. Perhaps there will be some future changes that will facilitate this.
Once an addon can force it's saved variables to save at will, interaction with the filesystem is one way to build a bridge to control external applications.
Also, perhaps in the future Trion may allow addons to access the web (as they can in some other MMOs), which would be another way to build a bridge to control local applications.
Never say never! ;-)