Sometimes the best solution is the simplest one that takes great inspiration from already successful precedents.
This is not a famous quote it’s just something I keep getting back to in many design inspiration that took something existing and made it better in every way.
Many tech writers are afraid Apple is going to ditch the 3.5mm jack for the iPhone 7 and I think they are overreacting. If Apple decides to do that, they are looking ahead and not behind. They will sell an adaptateur that will most likely make your old headphones work with the new technology not because they want to steal you 29$ but simply because they make these available to those that do not want to follow through with technological evolution.
Sean Nelson has came up with a great design of the Bluetooth dongle Apple could be selling for 3.5mm headphones. A simple puck that is rechargeable via Thunderbolt and comes with a snap to attach it to your coat or your pants. I like the design that is taken directly from another great product of Apple, the Watch charging puck.
Apple already has the software side ready, it will look like the Smart Battery Case in the Today view, like any other respectable Bluetooth headset do. Take a look at the Sennheiser Urbanite XL Wireless, they do exactly this to show its remaining battery life.