This new update, which comes in only at 7.8MB in size, is listed by Verizon simply as an "Android Security Patch added for additional security." Since this is a bit vague, it appears this update of the software to version I605VRALL4 patches the Exynos exploit that allowed people to root the phone and unlock the bootloader. But also included is an update to the radio baseband, which is said to help signal reception, even though Verizon does not list that in the support documents.
So what does that mean for you? Well, if you have (or plan to get) the Verizon Samsung Galaxy Note II, but don't have any intention to root it, then installing the update means very little and could be done without issue. But if you do have the device and it is currently rooted (or you will be rooting it), then then you may want to defer the OTA update for the time being.
There is now a way to root and unlock the bootloader even after the OTA update has been installed. You can read about it here.
source: Verizon Wireless and Droid-Life