I wouldn't call Sonic an actual threat or even competition to ATT or a phone company. They're one a Reseller/CLEC that NEEDS ATT to survive.
If ATT ever decided to bring Project Lightspeed back out of the closet and deploy full FTTH like they have in several of the Ameritech Regions Sonic would nothing more than an Earthlink/AOL trying to stay alive on dial-up, and later become history along with other resellers.
