Update: As spotted by SlashGear, WSJ has posted an update indicating that the unlimited plan is a decidedly limited time thing, with tiered pricing to come in the "not too distant future." Intrigue!
Update 2: And Macworld's confirmed that Verizon's iPhone WiFi data tethering pricing will be the same as all their other phones: $20 a month on top of your regular data plan, with a separate 2GB cap and $20-per-gig overage charges.
*Verizon is currently in the process of acquiring AOL, Engadget's parent company. However, Engadget maintains full editorial control, and Verizon will have to pry it from our cold, dead hands.