The deal, worth $39 billion, would make AT&T the nation's biggest wireless carrier in terms of subscribers, adding 34 million T-Mobile customers to AT&T's current 95.5 million. That number will dwarf the current market leader, Verizon, which boasts 101.1 million wireless phone customers.

Of course, before any major changes come to pass, the two companies will have to get regulatory approval from the U.S. government, which will attempt to ensure that the combining of two of the country's big four cell carriers will not hamper competition in the wireless carrier market. But once the dust begins to settle, how will the impact be felt on existing iPhone customers, and on Apple itself?

For existing AT&T iPhone users, the acquisition of T-Mobile will probably be a positive development--at least technologically. For one thing, AT&T stands to gain a plethora of existing cell towers in the U.S. This will allow the carrier to expand their network coverage in ways that wouldn't have otherwise been feasible, since building new towers is often a costly and time-consuming proposition, especially in dense population areas where iPhone users have traditionally experienced heavy network congestion.

Charles Golvin, an analyst with Forrester Research in Boston, said existing AT&T iPhone users should see increased service quality and expanded coverage if the merger is approved. T-Mobile adds "tens of thousands" of towers to the AT&T network in the short-term, and other assets over the long haul.