The AirPods are nice when you only want to carry your watch with you, and they will be replacing the remaining uses of the iPod, being able to play music and podcasts during your workouts. It is also very clever to keep the pod name alive after the iPod has withered away. We will see, with the advances in battery durability, whether AirPod batteries will age faster than cables will fray, as it will probably not be worth it to replace their batteries1, but I would be surprised if they match the 10 years I got from my earphones.
As a technology, they seem to be designed with the watch in mind. For the phone, an alternative where the wireless earpieces could be charged and paired via lightning, and you could still listen to music while charging, might be better2. But this is something Apple forbids, clearly indicating that Apple wants watch compatibility dearly.