More on this subject. Yesterday AT&T announced it was acquiring T-Mobile for $39 billion, creating the largest wireless carrier in the U.S. by far and reducing the number of major cell-phone serviceproviders from four to three. The news has dominated the news cycle, taken telecom stocks on a roller-coaster ride, and left customers on both carriers dazed and confused. How will the merger affect mobile users in the U.S.?