One happy side-effect (for Jobs) of Apple not running a network was that AT&T got the blame when there were bandwidth issues due to heavy demand for data, not Apple. ("I love my iPhone, but that damn AT&T network.....")
I originaly thought the iphone would be an iChat client running only on data via a network. With facetime and iMessage it looks like that's the way things are heading...
I think the implication of the article is that it would not use an existing carrier at all. Republic wireless still relies on traditional cell phone networks to handle calls/data/texts when not in range of wifi.