Ever since T-Mobile promised to introduce a Galaxy S III that supports LTE over Band 4 (1700MHz AWS), we've been scouring FCC docs for signs of its rumored March 27th arrival. Well folks, that day's now come, as Samsung SGH-T999L has just cleared the regulatory body, complete with readiness for LTE Band 4. The phone's model number pegs it as a natural successor for T-Mobile's original Galaxy S III (SGH-T999), and it also carries telltale support for HSPA+ over the 1900, 1700 and 850MHz bands. Curiously, the handset also supports LTE Band 17, which is common amongst phones for AT&T -- at the very least, this should add value for those willing to skirt those silly unlocking laws. Now, the only question that remains is how quickly this phone will become yesterday's news.