By the end of the first day when the amount of destruction became obvious, my husband said the folks in the city should be taken (forced if necessary) to the coast and housed in tent cities, otherwise really "bad" things (disease, etc.) are going to take place. I have seen no effort to move the Haitians out of or away from the rubble, decay, and death zone. Who knows how many bodies are buried in those collapsed buildings? It's going to get very ugly, very fast, and yet no one seems to be "in charge."
No one's stopping the people of Port-au-Prince from leaving all on their own. In fact, I saw just that on the news a couple of nights back.
Just as in New Orleans, most folks have the plain horse sense to get the hell out, without having to be "moved" by the authorities.