One of he big custom ROM's available for the HTC One just got last night it's own KitKat release. Android Revolution HD Sense 5.5 KitKat 4.4 has been available and with that comes a lot of HTC One fans running around to flash.
I won't go over and hash all the details out about KitKat but it's done and it there. You've all seen the updates, the new features, the increase performance and what not. Suffice it to say that if your in the mood to try KitKat for your HTC One head on over to XDA.