I finally got it changed! For those that may be wondering how to get rid of the default signature ( Sent from my Verizon Wireless BlackBerry ), here is your how-to...

First, with Verizon, you can't change this on your BlackBerry. You also cannot change this in your normal Verizon control panel. Instead there is a special admin for the email accounts, here

apparently when you set up an email account on your blackberry, you also are setting the same options here... but this has options the BB can't control directly. Odd.

The next challenge - to log in to that magic vzw control panel, you need a password. I had to contact Verizon by phone to get mine.

Then, once logged in, it was very simple ... click 'edit' on the existing account and enter a new signature. 

For me, I don't always want people to know I am not at my desk when answering or sending email. Turning off the annoying mobile confirmation messages and then changing the signature to one similar to my usual outlook email footer, I am now officially BB-cloaked.