ATT is throwing a bone to existing customers eager to get their hands on a new smartphone. The carrier has announced that postpaid subscribers who were under contract as of January 18th can upgrade to a new device immediately for $0 down through ATT Next. ATT is now opening Next to more customers, a move its positioning as a reward for their continued loyalty. As for brand new subscribers (those who signed a two-year contract after January 19th), ATT is shortening the wait for device upgrades to 20 months.