For a long time, the HTC One S was one of the most compelling phones on T-Mobile. That really tells you something about the lineup America's smallest national carrier was working with last year. There are plenty of these devices walking around, so today's update will be good news for many. That battery life problem introduced in Jelly Bean should be taken care of finally.
The update will come via an OTA, which begins rolling out today. If you don't want to wait, hitting the update button in settings should actually do something for once. The new software version can also be installed over USB if need be.