The Verge talked to Dave Burke, Google's Director of Engineering for Android, who has given a rundown of all the changes Google has made to the camera with the new update. The top of the list is speed all around. The app loads faster, autofocus has been made much faster, and simply taking photos is faster, because Burke says the app has been shifted from slower shutter speeds towards faster speeds, especially in the daylight. The camera had been optimized more for night shots where it could use a longer shutter to get better pictures, and rely on the optical image stabilization to keep the quality up, but that led to motion blur and other issues in daylight. With the autofocus, exposure, and white balance fixed, you remove motion blur problems and make everything faster in general.
Additionally, there is a new progress bar on HDR+ photos, which helps you know how long it will be to take a photo, since HDR takes longer in general. Colors and contrast have also been improved in the update. Colors look more saturated, and Burke says the aim was to make images "pop" more. Overall, the pictures look better all around.
Google says that the Android 4.4.1 update will begin rolling out in the next few days. As we've learned, rollouts can take a couple weeks to complete, but we're sure there will be a manual update package available soon enough.
source: The Verge