An irony is that while the phone companies are screaming to regulators that VoIP is killing their rate base and the like, hardly anyone bothers to mention that to use VoIP you gotta have a broadband Internet connection, and for most people that's DSL.
And where do most folks get their DSL from? Ta dah! The phone company!
Much of the competition talk really relates only to all of the gadgets and services, not to the fact that they're mostly being provided by a relatively small (and shrinking) group of very large telecom conglomerates, who are trying to set all of the rules of the game across the board.