Thanks for posting this tutorial. I had lost root during the jellybean update so have been checking the 'How To: Root your Motorola DROID Bionic' thread occasionally for updated methods, and saw the recent post by 'chuck54' directing me here.
Very easy steps, especially with previous virtual machine experience.
One thing to note is that it appears to be important to hit the volume up, down or power while the device appears to be rebooting.
The first time I attempted this, I wasn't paying attention to the process and my phone completed the false reboot, and I hit the vol up/down after it had completed. It wasn't rooted.
The second time I hit the buttons right when the virtual tiny linux machine said to, which happened to be at the same time the phone was displaying the typical reboot animation. I didn't see any notifications when hitting the buttons, yet afterwards I had root access again.