Because of the isolation of Darfur, and the reluctance of the Sudanese government to allow relief organizations in, several hundred thousand of the million refugees are expected to die no matter how much of an aid effort is made for the rest of the year. The government backed Arab militias are still wandering around, looking for black African villages they  have not looted and burned yet. The Sudanese are not willing to accept any UN peacekeepers, and are only reluctantly allowing journalists and aid workers in. These foreigners will probably have to face possible attacks from the armed Arab tribal militias wandering around on horses and camels. 

Chad has brought more troops to the Sudanese border, and this is discouraging the Sudanese Arab militias from crossing into Chad to rape, kill and rob among Sudanese refugees.