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.
He said:
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.

Comments:
mickmel
07/19/2011 12:55 pm
I would expect it in a few days. They just updated Google Earth with SS yesterday, and maps usually follows a few days later (though this is a rather unique case, so it's hard to say for sure). http://www.gearthblog.com/blog/archives/2011/07/south_sudan_is_on_the_map_and_now_i.html
James Holden
07/19/2011 11:10 pm
I understood that defining the border was going to take a long time due to various disputes over where the boundary actually was.
Barry Schwartz
07/19/2011 11:20 pm
Not really, Google has a solution for that. See how they handle territory disputes.
GoogleGator
08/09/2011 06:52 pm
"Typically quick"? As of today, a full month after South Sudan established independence, it's still not on the Google Maps site. Ridiculous. Even if parts of the border are in dispute, they don't need third-party or on-the-ground confirmation to draw a frickin' internationally-recognized line.
Bob Pond
08/20/2011 12:59 am
August 19, 2011. Still no indication on Google Maps or Bing Maps that South Sudan exists. The map makers are just too busy to deal with something as inconsequential as birth of a new nation.
Waldir Leôncio
08/23/2011 04:21 pm
According to Mabasa on the Gmaps thread (see post link), both Google Earth and the Earth layer on Google Maps show South Sudan. It shouldn't be long.