I earlier mentioned that in lieu of the Sudanese government's objection to an international force, Middle Eastern Nations should rise to tackle the challenge of Darfur. While it would be nice if they could, most Muslim governments are either at odds with Sudan, do not have the military capabilities to lead such a mission, or most unfortunately, just don't give a damn about the suffering of their fellow Muslims if it is not tied to Palestine or Iraq, Israel or America.
That leaves the world with other options. One such suggestion, as mentioned in the Economist magazine, is for China to lead the mission. China has the power and capability and could also utilize this catastrophe to improve their clout on the world stage.
If this is still not acceptable to the Sudanese government, a last resort option I suggest is born from the fact that the Sudanese government has quelled the people of Darfur's basic human rights. The region of Darfur is predominately black African. A government must protect all of its citizens to the best of their ability, no matter what background they are from. Because the Sudanese government, rather than protect the people of Darfur, has made efforts to persecute them by aligning their own military with local janjaweed militias, the United Nations should, with immediate effect, consider Darfur a country to itself, with their own right for self determination.
Instead of dealing with Sudan, you're dealing directly with Darfur. A subsequent referendum should be held on whether to rejoin Sudan as one country, or become the independant state of Darfur.
I know it's a drastic measure, but the Sudanese government has left the world with little other choice. The mere threat of recognizing Darfur as independent of Sudan may just kick the SOBs in Khartoum into action.