Once known as Operation Flashpoint 2: Dragon Rising, it seems as though the '2' has been dropped.The original developers of Operation Flashpoint, Bohemia, aren't involved with the project, and are instead focusing on ArmA, the series of spiritual successors. Apparently they are in doubt over whether this new Operation Flashpoint, developed by Codemasters, is an official sequel.
http://www.shacknews.com/onearticle.x/57454