Apple is planning on adding new features to the photo editing portion of their mobile devices. While most of these have been available already as third party apps, the update will integrate them into the devices OS and allow access from the lock screen. This feature will reduce the fumble time required to take a picture with the iPhone.
Something completely new to this update will be the duel use of the volume control as a shutter control. This after third party applications asked apple for the feature and were denied.
Additionally an upgraded photo app will be available once logged in. Though these will probably not stop users from using Photogene and Snapseed, it should increase the basic functionality of the mobile devices.
A few changes to Photo Stream are also planned, which is part of iCloud, a photo syncing software. The plan is that this will sync all new photos from mobile devices to your Mac or PC.
So while none of these features is groundbreaking, this is still definitely an improvement, especially the lock screen access and new shutter button. However, the photo editing changes will likely not be noticed by users already utilizing third party apps.