Count Jason Snell among the headphone jack removal nay sayers.
Jason starts the headphone segment (at 51 minutes and 44 seconds) of the latest episode of Upgrade with a very rational stance of "This is just a rumor. Let's wait and see what happens." But then he proceeds to get himself worked up into what I think is fair to call "a lather" talking about the issue. His constant refrain is "Tell me why Apple would remove the headphone jack."
I think the "why" is obvious. It's because wireless headphones will eventually be better than wired headphones. Right now wireless headphones are objectively worse than wired headphones in almost every way, but Apple has the power to move this technology forward. Any short term pain the user feels from this change (lightning headphones, 3.5mm to lightning headphone adapters, having to put up with expensive/flaky bluetooth headphones) will be forgotten in a couple of years.