The story says that the producers are currently casting these roles and that Cox is at the top of the list. There is no other information aside from that.
Based on JRR Tolkien's The Hobbit, is the story of Bilbo Baggins, who is seen in Lord of the Rings trilogy. The Hobbit follows Bilbo as he first encounters Gandalf. He is somewhat unwillingly swept off on an adventure to the lonely mountain to rid it of the dragon, Smaug. The dragon is guarding a treasure of enormous value that he had firstly taken from the dwarves who once lived there. A major battle shortly, ensues.
The Hobbit is slated to be released in November 2011.