I got my Passport last weekend and ended my 10+ year relationship with VZW on Monday. My wife did the same bringing her Verizon branded z10 over with no issues. Since we brought our own devices, we have no contract and are saving a lot of money too. It was an easy decision given those factors and the portability of phone numbers today. We can always easily go back if things don't work out with AT&T.
Love my Passport. BlackBerry has a winner with this one.