Carbine killed this addon in Build 6731 (6/13/2014)
It was done humanely and it didn't suffer, options for mouse and keyboard turning speed have been added to the default UI.
CameraSpeed allows the player to control the rate at which swiping the cursor in mouselook mode or using the turn keys will pan the camera.
Default speed modifiers for both are 1 (100%).
The addon allows values within the limits accepted by the client.
10% to 250% for mouse turning speed and 20% to 290% for keyboard turning speed.
Use /camspeed to bring up the options.