Verizon working on Voice over Rev A, would match AT&T's HSPA 3G network
This article contains unofficial information.
Verizon executive Brian Higgins says that the carrier is working on a way to allow EV-DO 3G connections to handle voice and data at the same time. While there is no time frame fo when we might see this accomplished, the so-called Voice over Revision A (VoRA) would allow voice to be transmitted back and forth alongside data similar to what AT&T and T-Mobile can do with their HSPA 3G network. Some Verizon models like the BlackBerry Tour and the G'zOne Ravine already use EV-DO for PTT functions.
source: electronista