I think this is a misunderstanding. Phone companies are looking to replace traditional telephone routing with VoIP, which uses IP addresses, as it runs over IP. Traditional telephone numbers are still used as the endpoints, and there's been no interest in substantially altering this.
I know that I get VoIP straight to my house; pretty much everyone in my town does. The phone lines around here are mostly unused. Everyone has a modem with an
RJ11/6P2C output that allows normal home phones to run over VoIP. Inside the house, phone calls behave traditionally, and the modem converts the signal to VoIP. The only downside is that if the internet goes down, so does the telephone service, but for the past decade it's been very reliable.
Still waiting on IPv6, though. Fiber optic with no IPv6, sosad.