There's precisely zero doubt that AT&T will be supporting LTE waves in the not-too-distant future, but it looks as if "the future" may be drawing closer than anyone had ever imagined. Or else the carrier's just really, really proactive. Based on the leaked slide above, it looks as if AT&T is already beginning to transition its current crop of SIM cards to "those that will also support LTE devices." Naturally, the iPhone 4 is omitted from all of this due to it using a
