Another adapter!!! More cash!!!!
It's beginning to look more and more like Apple will indeed kill the 3.5mm jack. I personally wouldn't be opposed to the idea; while it would make the iPhone incompatible with everyone's non-Bluetooth headphones (a large majority of headphones), clearly Apple would release an adapter that, as you said, would likely mean more cash for the company-- assuming they don't bundle in the adapter with the iPhone 7. Either way, an adapter (from lightning to 3.5mm) seems like a common sense move if they kill off the 3.5mm jack.
Really, though...think about how long 3.5mm jacks have existed in devices. It's a technology standard that's inevitably going to evolve at some point. There are clear benefits to this proposed lightning solution, such as thinner devices, increased power consumption available to headphones, digital tuning possibilities, etc. I think Apple's purchase of Beats will play a large factor in their evolution of the headphone standard. However, Apple would likely bundle in lightning earbuds in the iPhone 7 box, so everyone would have a pair of compatible headphones right off the bat-- no adapter required for the stock headphones.
As a user of both Bluetooth earbuds and headphones, these devices seems to absolutely be the way of the future. Whether Bluetooth remains king or another standard comes along remains to be seen. Either way, benefits for wireless audio are obvious. Apple sent a message with the rMB that they envision a no-wires approach to all devices, eventually. While they might keep the 3.5mm on the rMB-- it's debatable they will since they don't need the extra thinness-- the benefits for a thinner iPhone seem to make the most sense. I wouldn't be surprised if the next update to the rMB kills off the 3.5 jack entirely, though.
As the shift to wireless headphones/earbuds becomes more and more prevalent, the fact that they killed the 3.5mm becomes a moot point, anyways. Most people will begin to purchase wireless headphones/earbuds as they become more and more affordable, an inevitability for the tech industry. Maybe in 3 years you'll see bluetooth headphones for $9.99 at gas stations, who knows. Eventually, lightning headphones will be exclusive to audio products that can benefit from the digital capability and sound quality enhancements of a lightning port solution as well as the increased power consumption possibilities (integrated DAC features?).
Like I said, whether or not Apple will make this change in the next update to the Skylake rMB is debatable. But Apple always seems to see the way of the future ahead of what many people are comfortable with (see: 30-pin to lightning), and while backlash will be significant at first, I think most of us who have used Bluetooth headphones know that wireless really is the way of the future. The ones who don't care much will just use the stock lightning headphones that will continue to be included, and the ones who do care will have all the more reason to purchase a superior, increasingly affordable (in time) Bluetooth audio device.
