Tmobile does not have LTE yet. In the meantime they are transitioning from the HSPA+ 1700Mhz (non iPhone compatible) to 1900Mhz (iPhone friendly) bands. HSPA+ is not 4G LTE, but it is fast enough to get great 3G speeds.
Correct, but they do plan to rollout LTE in 2013. Just trying to plan ahead.