HTC announced last year that it will update HTC One developer edition, Google play edition (GPe) and regular HTC One with Android 4.4 KitKat and offered time frames for the same. HTC has so far updated the GPe and developer edition and the regular HTC One update should start by the end of this month.
French telecom operator SFR has announced that Android 4.4.2 KitKat update for HTC One is now rolling out, the update is available from the morning according to SFR. HTC may be on-track with the Android 4.4 update for HTC One as promised and might soon reach other carriers.
The SFR announcement confirms that the update is rolling out in-time but there is not sign of the update in other regions of the world. The Android update for HTC One will bring Android 4.4.2 KitKat, BlinkFeed improvements and more importantly the HTC Sense 5.5 update, there is no official changelog as of now.
The update is OTA and you can check for the update by going to Settings –> About phone –> Software updates on your phone.