The matter of the border delineation dispute and arbitration thereof regarding the Abyei District of Sudan has been concluded... at least if both "north" Sudan and "south" Sudan live up to their words accepting the arbitration results.
Sudan (the "north") got the border drawn in such a way that most of the more important oil fields are on their side, which certainly makes the P.R. Chinese happy. Greater Nile Petroleum Operating Company (GNPOC), the operator there, is a consortium led by China National Petroleum Corporation (CNPC).
Autonomous South Sudan got acceptance that at least the major part of their claim of what constitutes Abyei is correct, and did get recognition of most of the fertile grazing land being within Abyei.
Where this all really matters is when it comes time for the twin referendums in 2011.
At the same time, Abyei will vote as to whether it remains part of "north" Sudan or joins the autonomous "south" *and* all of the "south" will vote as to whether to remain a part of Sudan or if it will become Independent South Sudan.
Please see The Weekly N&C for June 22nd, 2009 regarding this matter in greater detail.