This thread is bizarre.
Why are 50% of the people assuming this means ditching the headphone jack?!? Its just Apple enabling a feature for companies to use if they want on the already existing lightning port. Its ADDING a feature to the phone you already own, not removing the headphone jack, jeez.
It would enable even an iPhone 5 to output 24bit digital audio and receive it, which it currently can't without a 3rd party audio interface. This could give you the option of using the headphone jack, an audio interface like the Apogue Duet or a headphone with the DAC built in, and the headphone could also have a battery built in to charge the phone (weight dependant)
You probably won't get high quality headphones using this, just over priced junk but still its a nice idea and not instead of something else (its like liking the headphone jack was going to be removed when Apple introduce bluetooth audio ffs!)
and on a second note, this thread has taught me just how many people are sat charging their iPhones and listening to music at the same time...a lot apparently!?