It's bad enough for AT&T that Verizon is allegedly set to unveil the iPhone on its own network come January 11. But if new reporting from the Wall Street Journal has any weight, Verizon is planning to pour some salt in the wound for customers bothered by AT&T's June, 2010 switch to data plan tiers. The unlimited data plan is coming back.

There was a good amount of grumbling this past year when AT&T announced that it was removing the iPhone's truly unlimited data plan—at a cost of $30 monthly—and replacing it with two different tiered data plans. The cheaper of the two allows a customer 200 Megabytes of data use per month at a cost of $15, and the more expensive plan caps one's data use at two Gigabytes of data for $25 monthly.

Going over the limits on either naturally result in additional fees: $15 for an additional 200 Megabytes of data for those on that plan, or $10 for an extra Gigabyte of data for those on the two-Gigabyte "DataPro" plan. And iPhone tethering, should one opt for that, would cost an additional $20 monthly on top of the $25-per-month plan.

Thus enters Verizon. According to sources speaking to the Wall Street Journal, the company is set to announce the return of unlimited data plans for iPhones—for those on its network, of course. Sources say that an unlimited data plan option will be offered for $30 monthly, an amount that's slightly larger than either AT&T's two current iPhone plans.

It's unclear whether Verizon, like AT&T, will be moving to a tiered pricing structure in the future—company executives have previously said that the wireless industry needs to move to tiered data structures. Or, as Verizon CEO Lowell McAdam has previously envisioned, a scenario where one buys a bucket of data use that's split between wireless devices of all kinds, be they cell phones, car services, et cetera.

And Verizon does employ tiered data structures exclusively for its 4G LTE network—at more expensive prices than the iPhone unlimited plan it'll allegedly offer. Users can elect to purchase either five Gigabytes of data for $50 monthly or 10 Gigabytes of data for $80 monthly on Verizon's 4G network, but there's no "unlimited" option to speak of.