What makes VoIP attractive is the lack of all the regulatory cruft that the POTS system has been burdened with after a century of regulation. E911 is just the most obvious and useful part of that stuff, so they use it as a foot in the door. Once the telcos have got that required, they'll move on to all the other stuff on your phone bill, such as the TDD relay service. Eventually your VOIP will be as full of taxes as your POTS bill.
