good for T-Mobile. they see the future and are trying to head off the coming competition. They still charge you regular rates for minutes and SMS, so not much gained by this other than improving call quality when your T-Mobile signal is low.
Carriers are moving towards pay by megabyte for wireless data. The carriers will all be dumb one day and it will be nothing more than a competitive business for voip providers. Lefar knows this and is designing Vonage's next generation services with that in mind.
The T-Mobile news is great actually for everyone in this space and moves us another small step towards the future. Thanks for sharing.