Since Facetime’s launch in 2010 the convenient video calling feature has always been Wi-fi only. The only workaround was using a jailbreak tweak, which required a jailbroken device.
But as like in the past, Apple is once again testing Facetime over 3G. We aren’t all to sure if they are planning to enable such a feature, but the continuing testing lets us know they are getting ready to. The latest proof comes from iDevice.ro, who took this screenshot from a iOS 5.1.1 error message. This comes to prove Apple has strings of sorts within iOS’s coding.
The only issue with Facetiming over the 3G network is the amount of data that it would consume at such a fast rate. Putting that behind I wouldn’t see a problem with Apple enabling the feature. As long as Apple warns their users or creates some max-usage settings panel, I wouldn’t see a problem at all.