Other than bug fixes there really isn't a whole lot going on in this update. Other than the dialer app being redesigned, the people app has also received a redesign in Android 4.4.3. The biggest change here is the addition of colored letter and people icons in place of pictures where pictures do not exist. Before all any contact missing a photo had a greyed out image. The new replacement images seem to be inspired by the gmail app. You should be able to grab the 4.4.3 ota update for your Nexus device by now.
image DroidLife