i am pretty sure it's the end of the headphone jack, IF the wireless headphones work really well. Traditionally Bluetooth headphones have always had a few quirks and annoyances (i still love mine) so if they fixed that i believe that people will see the benefits. It's kind of like the outcry when the very first iPhone did not have a keyboard at all. Only a Touchscreen ? WTF?
Yeah, that would be the case, if it only were not for the dozens of just touchscreen phones before the iPhone came out.
IMO, this could be the beginning of the decline of Apple (since smartphones make majority of apples profit)