The update won't bring any changes that you can see, but it remains important nonetheless as it opens up your handset for future updates. The build of Android on your LG G2 will remain at Android 4.2.2. It is possible that this update will be smoothing the way for the upcoming KitKat update.
Officially, today's update is said to provide FOTA enhancements to support future updates, and also includes Google enhancements. Yeah, we know you wanted this to be Android 4.4, but it is coming soon. Really.
source: AT&T via AndroidCentral