Late last month, a rumor surfaced that T-Mobile planned to absolutely wreak havoc on the wireless industry this year by offering to pay off subscribers’ early termination fees if they switch from another carrier. This rumor may have sent shock waves through ATT because an unnamed source tells GeekWire that ATT is planning to offer $200 to any subscriber who switches from T-Mobile… and only from T-Mobile. GeekWire says that the $200 bonus “would be in addition to up to $250 of the trade-in value of the switcher’s old device, under ATT’s existing trade-in program,” so it sounds like ATT really, really wants to limit T-Mobile’s ability to take away its customers. If ATT does go through with such a