Some of the people who received the update are now looking for ways to root their device. So here a step by step guide on how to root your Droid 4 with Android 4.0.4, Ice Cream Sandwich.
* Caution
The below procedure will not affect the data on your device. However, it is always advised to do a backup of the data on the device as a precaution.

How to Root the Motorola Droid 4
- Download - ICS404root.zip
- Enable the “USB Debugging” on your handset. Go to Settings -> Development -> Check the tick-box that says “Enable USB Debugging”.
- Connect the device in to your computer. Instead of using Mass Storage, change the type of connection to Camera Mode.
- Extract the contents of the file you downloaded (ICS404root.zip) into a folder anywhere on your PC.
- Windows users and Linux users have to follow different methods on this step:
- On Windows - Go to the extracted folder and double-click the “rootscript.bat” file to start running the script.
- On Linux – Go to the extracted folder and run the script named "runme_root_script.sh".
- Press Enter after you make sure that you enabled USB Debugging and also that the device is connected in Camera Mode.
When the script finishes running, your Droid 4 will be rooted. Now you will be able to run all the root-requiring applications available on the Google Play Store!!
Thanks should go to Rick#2 from xda-developer, who came up this simple tool.