The FCC has ruled that VoIP is an interstate service, in response to a petition from Vonage, one of the best known national VoIP providers.
This is very significant, because it snatches VoIP out of the clutches of state by state regulation (we've got 50) that could have easily sunk the service before it got started. State regulation would have been a nightmare, and at the least, would have increased the cost of service. At the worst, some VoIP companies would have just quit the business and potentially sunk the industry. There is no way VoIP could be competitive if each VoIP provider had to deal with 50 different sets of taxes and regulation.