Some are pointing to what they say are dramatic differences in how A&T and Verizon will handle FaceTime over cellular, while analysts argue the two approaches are nearly identical. Keyword: nearly.

Customers purchasing an iPhone 5 can sign up for Verizon's relatively new Share Everything Plan, with prices beginning at $40 monthly that includes unlimited voice, unlimited text, picture and video messaging, and a data plan that can be shared with up to 10 devices on a single account.

Verizon's news release pointed out that, "customers wanting to use FaceTime on their iPhone 5 can do so using any Verizon Wireless data plan allowance." Verizon still has some customers on old plans that can use FaceTime over cellular on an unlimited basis. But AT&T is only letting customers on its new shared data plans access FaceTime over cellular.

AT&T's Bad Rap

AT&T opened up a net-neutrality can of worms last month when it said it planned to offer FaceTime only to cellular customers on shared data plans. Customers have historically used the video chat application over Wi-Fi , but Apple's latest version of its mobile operating system, iOS 6, offers mobile broadband capabilities using FaceTime. The new iOS will be available for download Sept. 19 and will come pre-installed on the iPhone 5.

Groups like Public Knowledge are coming together against AT&T's moves in light of the mobile OS updates. John Bergmayer, a senior staff attorney at Public Knowledge, insisted that by blocking FaceTime for many of its customers, AT&T is violating the FCC's Open Internet rules.

AT&T's Bob Quinn said calling the move a violation is "another knee-jerk reaction," and said "those arguments are wrong." He said providers of mobile broadband Internet access are subject to two net-neutrality requirements: transparency and not blocking apps that compete with the provider's voice or video telephony services.

FaceTime Sucks Data

Weston Henderek, a principal analyst at Current Analysis, said AT&T and Verizon's positions aren't all that different. Both carriers are encouraging customers to sign up for their new shared plans and the FaceTime usage draws from an allotted bucket of mobile broadband.

"The reality of the situation is that FaceTime over cellular networks uses huge amounts of data. So if they were to say unlimited FaceTime over cellular, that's a burden on their network . Sprint is sort of caught because they are offering unlimited data, so this could have a negative affect on them if lots of people start using it," Henderek told us.

"But bottom line is the amount of data you use for video chat is many, many times the amount of data you use for a voice call. So it's equivalent to you or me making calls to 30 different people all at once."