North American markets have significant quantities of HTC One Developer Edition, and Google Play Edition; and their getting the Android 4.3 upgrades along with HTC One users from above the 49th parallel north isn't flying down well with US-based ones.
HTC released a series of tweets on the matter, over the past week. It's not looking good, if you've been using a carrier-tied HTC One, and are looking forward to that Android 4.3 upgrade. The way it works with carrier-tied handsets, is that HTC pushes its software upgrade to carriers, who then customize it, test that customization, and then push it down to subscribers.
HTC had hoped that US carriers would be done on the customization part by September 30. It's looking like they won't make it before that date, and the upgrade could drag on well into October. HTC didn't explain how Canadian carriers could get their work over with so swiftly, that their upgrades could roll out at almost the same time as they were pushed to Developer Edition users.
HTC also broke its silence on the long overdue software upgrade for Droid DNA. The handset will get an upgrade to Android 4.2.2 and the latest Sense 5 user-interface by "the end of the year."