Verizon may be looking to follow AT&T's lead with their tiered data pricing. While it is true that Verizon does not technically offer unlimited data (their plans are capped at 5 gigabytes per month), they are most likely looking to move to more structured and tiered data packages that will be offered with their smartphones.
According to Businessweek.com, Verizon's CFO, John Killian, is quoted as saying, "We will probably need to change the design of our pricing where it will not be totally unlimited, flat rate," which shouldn't surprise many as Verizon has stated this intention previously.
Verizon will most likely move to a tiered data plan when it launches its 4G network sometime later in 2010. The plans will potentially allow for more flexibility in your consumption of data, especially if you're a light user. But, for those who are heavy data users, you can most likely expect a price increase.
"Verizon’s customers for smart phones, like the Droid and Incredible, are using between 600 and 800 megabytes of data per month, similar to what iPhone customers consume," Killian said. It is plausible that the data tiers will be structured around these amounts for the average user.