On July 9, 2011, South Sudan became an independent state and on the 14th it became a member state at the United Nations.
Now that this has been made official, as per the United Nations, Google is rushing to revise their maps of Sudan.
A Google Maps Help thread asked Google to make the update. Googler, Daniel, from the Maps team said they are working on it.
We work hard to make our maps as accurate as possible and we do our best to ensure they reflect the on-the-ground reality. As maps are always evolving, we regularly review additional information and update when data becomes available.
Following the formal independence of South Sudan, we are in the process of updating our map and boundary data for the region. We look forward to publishing this updated data on our maps in the near future.
How soon is "near future"? I am not sure, but Google is typically quick when it comes to major events being reflected on maps.
Forum discussion at Google Maps Help.