HTC One with 64GB is an AT&T Exclusive, No Fooling
Here's a look at the video (jump to the 27 second mark to see AT&T's claim):
We're not trying to make a mountain out of a mole hill, though some non-AT&T subscribers might find this a deal killer. Without any expandable storage options like a microSD card slot, there's no way to add more capacity, so you'll have to make do with 32GB for the life of the phone. Most people probably won't have a problem with that, but it's a curious decision nonetheless, especially since Samsung's competing Galaxy S4 is available in 64GB form.