When you apply the Camera Shake Reduction tool, it analyzes the image in an attempt to figure out how the camera moved while the shutter was open. Once it recognizes the blur pattern, it can reverse engineer it, and sharpen things up. The demos have been impressive, but we're interested to see how it works. Apparently the function was working over a year ago, but was taking up absurd amounts of computer resources, so it was not included. Now, it's official, though.