HTC USA revealed information according to to which the on contract- HTC One devices would soon be getting the KitKat treatment, as the updates have already been send to the respective carriers and are now in the midst of approval process. As soon as the testing is done, and the update is certified by the carriers, it will be seeded to the devices.
But the time that the certification process would take up is still not known yet. Also the HTC One Mini on AT&T, and also Sprint & Verizon One Ma are in the integration stage of the update process, and it would take some time for the update to beout, so you definitely need to be patient. And as far as the HTC One Contracred devices are concerned it depends solely on your carriers, that how fast they can get it out for your device.