It doesn't come right out and say it, but we have a strong suspicion that the HTC PJ40110 -- approved by the FCC today -- refers to T-Mobile's version of the HTC One S. This model offers an AWS 3G radio, in addition to AT&T-friendly 850 /1900 3G bands, and its ID is just a slight nudge from the PJ40100 (global One S). The timing of this seal of approval lines up with T-Mo's spring launch aspirations, and this is one particular device (pun unintended but welcome) we can't wait to see in stores.
Note: There's also a lot of speculation that the PJ58100 is the One S for T-Mobile, and was approved by the FCC two weeks ago. Both models appear to share the same specs and radio sets. In our initial investigation, it looks like the major difference is in the location of the WLAN / BT antenna itself.