There is, however, a little more to the announcement: The actor will also provide the voice of the Necromancer of Dol Guldur, a character only briefly mentioned in the J.R.R. Tolkien novel but later revealed to be a manifestation of Sauron, the primary antagonist of The Lord of the Rings. That would seem to indicate another actor will lend his voice to Smaug (Deadline early heard it will likely be Bill Nighy).
The confirmation of Cumberbatch's role came shortly after Deadline reported that Luke Evans, who stars in the upcoming Three Musketeers, has been cast as Bard the Bowman, the grim-faced guardsman of Lake-town and heir of the last king of old Dale who ultimately slays the cunning and fearsome Smaug.
Director Peter Jackson's two-movie adaptation also stars McKellen, returning as Gandalf the Grey, and Martin Freeman as Bilbo Baggins. Other actors reprising their Lord of the Rings roles are: Cate Blanchett as Galadriel; Orlando Bloom as Legolas; Ian Holm as the elder Bilbo; Christopher Lee as Saruman; Hugo Weaving as Elrond; Elijah Wood as Frodo; and Andy Serkis as Gollum. The ensemble cast also includes Richard Armitage, Jed Brophy, Adam Brown, John Callen, Stephen Fry, Ryan Gage, Mark Hadlow, Peter Hambleton, Stephen Hunter, William Kircher, Sylvester McCoy, Bret McKenzie, Graham McTavish, Mike Mizrahi, James Nesbitt, Dean O’Gorman, Lee Pace, Mikael Persbrandt, Conan Stevens, Ken Stott, Jeffrey Thomas and Aidan Turner.
The Hobbit: An Unexpected Journey opens on Dec. 14, 2012, and The Hobbit: There and Back Again on Dec. 13, 2013.