As much as many would think an update from Android 4.0 to 4.1 is just an incremental upgrade, there would still be hundreds of improvements, tweaks, bug fixes and new features that will be added. Needless to say, devices released with lots of features like One X and One S will surely offer even more than they were advertised.
One good thing about HTC devices is that they always come with custom HTC Sense user interface making it even more appealing. Thus, we can expect that once this update will start rolling out, it will come with a new version of HTC Sense; currently, Sense is at version 4.0.
The October roll out is intended for the international variants of the said devices. Jelly Bean updates for both T-Mobile and AT&T variants in the U.S. are yet to be announced. But based on the history of HTC’s update rollouts, there might be just a week difference.