A couple of days ago a leaked memo appeared online which seemed to be confirming that Verizon will introduce a new $20 upgrade fee for most of their plan options. At the time, the memo came with verbal confirmation that this was a fee which was due to be introduced on April 4th. With the 4th being Monday it was always likely that if the information was correct, a confirmation from Verizon would come through soon enough and now it looks like that has just happened.
More leaked evidence of the change hit the internet earlier today and this was then followed by Verizon confirming to Droid Life that the change is happening and is due to take place starting from Monday, April 4th. According to the statement from Verizon, the reason for the introduction of the new $20 upgrade fee is to "cover our increased support costs associated with customers switching devices." Suggesting that smartphone owners are effectively upgrading too often. In terms of how the fee will be implemented, the Verizon statement does detail that those who are planning to upgrade through Verizon can either "pay the charge when they upgrade, bill it to their account or trade in an old device to offset the cost." So presumably, you will not have to pay it at the time of upgrading if you don't want, although it will have to be accounted for one way or the other.
For those that did miss the coverage from earlier this week. The short of it is that Verizon customers who are looking to upgrade on either a 'Device Payment' plan, a 'Device Payment Annual Upgrade' plan or even those who upgrade and purchase the device at full retail value, will all be liable for the new $20 fee. The only exceptions to the rule seem to be those who switch from another carrier, as they will not be liable for any upgrade fee and those who upgrade on a two-year contract. Although, those on a two-year contract do already have to pay a $40 upgrade fee, twice the cost of the new few which will be introduced on Monday.