Is Apple Testing iPhone 4G and Associated Networks with Verizon?

A rumor indicates that Apple would be testing for around 2 months a prototype of its iPhone 4G on Verizon's networks. It would be a revanche or come-back for this US carrier as it originally did not want to adopt the iPhone 2G and team up with Apple. Cupertino then went to AT&T with the associated success we know for both companies. Despite very aggressive anti-iPhone ads from Verizon, its CEO would be doing its best to please Apple and could have already visited Apple executives several times over the last few months.
This rumor is not really surprising and was already reported before when mentioning the on-going discussion between Apple and AT&T to further extend the exclusive partnership. While Apple might want to go carrier-free in order to gain access to a larger number of customers, AT&T knows how many customers subscribed to its subscription plans thank to the iPhone. However, the repetitive problems faced by AT&T for deploying its 3G network and catching with the increasing bandwidth traffic could support Apple to end this exclusive partnership at the end of the year, as originally negotiated.