It looks like Warner Bros. is hot on their Sherlock Holmes franchise as Deadline reports that they're moving forward with the third installment. The second film Game Of Shadows hasn't even hit theaters but the studio is looking to hire Drew Pearce to pen Sherlock Holmes 3. Pearce recently co-wrote the Iron Man 3 script with director Shane Black. Also, writing The Runaways script for Marvel Studios.
It seems like a good way to push forward a solid trilogy before the heat wears off and director Guy Ritchie looses interest. Ritchie's many other film projects [The Real RockNRolla, Lobo, Dirty Dozen, Sgt. Rock] have been put on hold because of the Holmes series. Robert Downey Jr. and Jude Law have previously stated they'd both be on board for a trilogy. It's currently unknown if either Noomi Rapace or Rachel McAdams would be returning for the next installment.