>Another is that it's harder to charge a phone if you have headphones plugged into its sole port.
>The new specification, due this quarter, adds features to ensure a USB headphone doesn't drain too much battery power...
The second isn't an answer to the problem of the first.
>As a result, with USB headphones, "the difference in battery life is negligible" compared with 3.5mm audio jacks.
It's not negligible because, so far it seems like we are going to have a choice of a charging cable or an audio cable. Currently I can listen to audio and charge my phone simultaneously, so in an hour my net battery life is +25%. The best the either/or situation can deliver is -0.0% (but likely something more along the lines of -5% in an hour of audio listening.)