It is uncertain why the update causes the phone to brick but there have been comments on blogs and forums all over the internet reporting it, so we know it’s more than just one odd case. Verizon/Motorola have yet to come publicly with a statement about the bricking so in the meantime, if you’re worried – you should hold out from getting the update just yet. Or if you do, make sure you back up your device just in case. Worse comes to worse you can just take it to your local Verizon store and see what they can do for you.
Stay tuned for more details.