April 1 was a momentous day for the entire US wireless industry, but August 2 will also go down in the history of the nation's third-largest mobile network operator as a crucial stage in the transition to a "supercharged Un-carrier" fully equipped to challenge the Verizon/AT&T duopoly.While T-Mobile and Sprint technically , the two brands were left largely untouched until yesterday. As highlighted by T-Mo EVP of Consumer Markets , the "most monumental day in T-Mobile's history has arrived", with Sprint's "iconic yellow lights turned off one last time" and "one powerful, ...