AT&T announced today that it is expanding FaceTime over cellular to all tiered data plans. The news came via a posting on AT&T's Customer Blog:
When FaceTime over cellular launched in September 2012, we explained that we wanted to roll it out gradually to ensure the service had minimal impact on the mobile experience for all of our customers.
As a result of ongoing testing, we're announcing AT&T will enable FaceTime over cellular at no extra charge for customers with any tiered data plan using a compatible iOS device.
This means iPhone 4S customers with tiered plans will be able to make FaceTime calls over the AT&T cellular network. AT&T previously made FaceTime over cellular available to customers with a Mobile Share plan and those with an LTE device on tiered plans.
The additional support for FaceTime over cellular isn't happening today, however. AT&T states that it will begin the update in the next few weeks and gradually roll out the feature to users over the next few months. There is nothing AT&T customers need to do on their end to take advantage of FaceTime over cellular.
Once the rollout is complete, the only AT&T customers without FaceTime over cellular support will be those on grandfathered unlimited data plans.