AMD and Eidos have managed to get ready with the patch which will bring both TrueAudio and Mantle to the Thief game and should be published tomorrow morning, March 18th.
Although there are still no precise details, it appears that the patch for the Thief game will be accompanied by a new Catalyst driver from AMD. As you already know, the new patch will bring support for AMD TrueAudio which will definitely make sense in the Thief game and should bring a new "convolution reverb" effect which should simulate the echoes in the game and thus provide much more realistic sound to the game.
The new patch will also brings support for AMD Mantle API for Thief and we are definitely looking forward to see how much performance gain we will see. The TrueAudio feature on the other hand is limited to R9 290X, R9 290 and R7 260X graphics cards.
In any case we will see and hear more tomorrow.
Source:
AMD.com.