When the iPhone debuted in June 2007, Apple restricted application support to only those that Apple and AT&T had determined were not likely to overload AT&T's digital networks. Now, two years later, AT&T has agreed to allow Skype for iPhone onto its networks, potentially giving up millions and millions in phone-plan income.

The company has managed to control gossip about the decision. But you have to wonder: Did AT&T reluctantly forego a big chunk of revenue, or is this an eager plan to lure new phone buyers away from cheaper models by offering them an iPhone with unlimited calls for under $80 per month in AT&T and Skype fees?

Update: As noted by a reader, Skype's restriction to Wi-Fi rather than 3G or EDGE wireless networks limits Skype's availability to mobile users. The Wi-Fi requirement was referenced in an earlier version of this post, but the Standard has clarified the 3G/EDGE issue.