Lots of things, potentially. From GigaOm:
In early May, the tech world was buzzing about a rumor posted on Secret that Apple might make earpods with biometric sensors for heart rate and blood pressure. The only problem was that the Secret post was a hoax written by someone with no knowledge of Apple’s plans. I don’t have any particular inside knowledge about the R&D labs in Cupertino either, but perhaps the rumor wasn’t as wild as it first seemed: Apple, even if it isn’t planning to release some kind of advanced wearable headphones, has almost certainly toyed with the idea.
Apple is interested in health technology and it seems as if Apple will launch an wearable wrist computer is coming later this year. Many aspects of that device – such as its reported reliance on biometric sensors — could also be included in headphones, as well.
The elephant in the room is Apple’s $3 billion acquisition of Beats Electronics, the market leader in high-end headphones. Beats doesn’t seem to fit exactly in with Apple’s product philosophy, but it’s hard to see Apple killing a wildly profitable line of products with billion-dollar annual revenue just because it wanted the associated streaming music service. And the firm that designed Beats, Ammunition, has confirmed that it is no longer working with the colorful headphones after the Apple sale, which would imply that Apple has brought R&D for headphones in-house. It does look as if there will eventually — at some point — be a new Beats design, this time headed up by Apple. So what’s going to be included?