In a rather unexpected move, AT&T has announced a momentous policy change that will enable VoIP iPhone applications to run on its wireless network. There are already quite a few available in the App Store, like Skype, Vonage, and Truphone, but up until now users who wanted to use them had to do it over a Wi-Fi connection.

The decision applies only to Apple's smartphone and is supposedly based on the "evaluation of customer expectations." Curiously the FCC is considering a proposal to formalize network neutrality principles, which would extend to wireless networks, and AT&T's reversal fits nicely into those rules. Furthermore, the government agency has been looking into carrier's business relationship with Apple to determine whether or not anti-competitive behavior has taken place.

AT&T's change in policy has no effect on Apple's rejection of the Google Voice application for the iPhone, nor it means that video streaming or other high-bandwidth applications over 3G will be allowed. Still, it's an important step towards a more open model.