From Wikipedia:
"Southern Sudan produces 85% of Sudanese oil output. The oil revenues according to the Comprehensive Peace Agreement (CPA), are to be split equally for the duration of the agreement period. Oil revenues constitute more than 98% of the semi-autonomous government of Southern Sudan's budget"
From Amnesty International:
http://www.amnestyusa.org/business-a....do?id=1081006
The South produces 80% of all oil, and the central government in Khartoum gets 50% of all revunues from oil produced in the South.
If the above is true, I would be very very surprised if the South was granted sovereignty and allowed to take the oil with them. It would decrease Khartoum's revenue from oil by 2/3.