we got an update for the d4. it seems like a bugfix to me. So far 4g seems to be more stable after the update, the ui is def smoother, and the unit is running cooler.*No root required.1. Download the file to the root of your SD card.
*We have been told that Voodoo Rootkeeper will keep root and that other root methods work as well after updating.
2. Turn phone off.
3. Press both Volume keys and Power at the same time to get to the bootloader menu.
4. Scroll down to “Recovery” and press Volume Up to select it.
5. When the Android and exclamation mark appear, press both Volumes at the same time.
6. Scroll down to “apply update from sdcard” and select it with Power.
7. Scroll down to “Blur_Version.6.13.215.XT894.Verizon.en.US.zi p” and select it.
8. Watch the update install. Reboot when it finishes and enjoy!
info source: Download: Motorola DROID 4 Update 6.13.219 – Droid Life