AT&T is offering a bit of clarification on the rumors involving a standalone feature offering FaceTime over Cellular for an additional charge: the iOS6 feature (due out this fall) will actually be included at no extra cost, but only for those customers who opt for the Mobile Share plans. Anyone on the grandfathered unlimited data plans or traditional tiered offerings will only be able to rely on the good 'ol WiFi whenever they feel the urge to use Apple's video chat service. From the looks of it, it seems that AT&T is hoping to conserve the amount of network bandwidth that would be chewed up by unlimited customers, while also having it function as a value-added feature for its newest shared data plans. In terms of usage, this FaceTime capability will use up part of your data allotment (instead of minutes). So, the good news is that the feature is free -- the bad news is that it won't make unlimited users any happier. Find AT&T's official statement below.