Someone should. It would be nice to see the AU do it. I would suggest a coalition semi-modern African troops (like the Nigerians, Ghanians, Ugandans, South Africans, and/or Rwandans). Probably not going to happen though, as he's strolling around Addis Ababa like he owns the place.
With you guys and us yanks in Iraq and Afghanistan, its a bit difficult to launch such an intervention, and old Bob knows it. Maybe the Frogs could take it on