HTC Americas President Jason Mackenzie just tweeted the following.
Lots of questions re 4.3 release for One. We r wrking hard (needs cert) to release 4.3 across all US, Canada skus by end Sept. DNA as well.
— Jason Mackenzie (@JasonMacHTC) August 19, 2013
And there you have it. Just a day after 4.3 was promised for the developer edition HTC One by Mr. Mackenzie, he's clarified that statement to include all US and Canadian Ones (and the Verizon DROID DNA) with a deadline before the end of September.