Apple iPhone 6s rumored to come with Force Touch and the Taptic Engine68
Using haptic feedback on the iPhone 6s in the form of the Apple Watch's Taptic Engine technology would allow users to feel vibrations in varying strengths. With the phone in your hand, a subtle vibration might be able to give you a clue about a notification without having to look at the screen on your handset. And this could be quite an interesting tool for game developers to use (as Force Touch could be, as well).
One rumored feature, a dual rear-camera system similar to the Duo camera used on the HTC One (M8), has been allegedly shot down by Apple because of the lack of room inside the device to fit the required components. As it is,the protruding camera on the new iPhone models created something of an uproar when first introduced.
This is the third time we've seen a rumor about the next-gen iPhone employing Force Touch, so there could be something to this speculation.