A year from now, AT&T will be a very different company. Barring regulatory blockades, it will own DirecTV and two newly acquired Mexican telecoms. And, by then, the No. 2 national carrier may be known as much for gadgets in people's homes and cars as in their pockets. During the fourth quarter, AT&T added 1.3 million connected devices, including 800,000 LTE connections within vehicles, payoff from its entry into smart-home technologies.