AT&T has verified to MacRumors that customers currently holding unlimited data plans will be able to keep those plans when upgrading to the iPhone 5, and will now get 5GB of data before being throttled. On 3G smartphones, users would get throttled after 3GB of transferred per month.
Additionally, unlike Verizon, which is no longer offering unlimited data customers discounted pricing on new handsets -- even with a new, two-year contract -- AT&T will honor its subsidized pricing policies even for its customers with unlimited data plans.
AT&T customers who are eligible for an upgrade can order an iPhone 5 16GB for $199 beginning on Friday through the Apple Online Store or att.com/iphone. Users can see if they're eligible for an upgrade by checking AT&T's upgrade eligibility checker.