I had the same issue until I realized I'd turned off USB Debugging. After that, it worked for me first try with my phone connected in "Charge Only" mode. You can select this by pulling down the status bar and tapping the USB item when it's plugged in.
I wasn't sure how I felt about Motorola, but this update may have put them back into my good graces!
Received the update this morning. Everything went smoothly, and the phone seems to be running great. I just can't seem to get aRoot to work for me. Debugging is turned on, and I'm in "Charge Only" mode. The command runs, but the phone never restarts. I've tried it several times with no success.