Nooo, that is inherent in their being. They are somewhat better than a non-ethereal item of the same type; the kicker is that they cannot be repaired by any means.
There's only one way that an ethereal items durability can go up, and that is with the suffix of "self-repair" or for throwing weapons "repleneshes quantity". otherwise, your outta luck.
I forget if this ever worked or not, but selling ethereal items to vendors and buying them back again? I'm not sure how this works wiht regular/magic/rare/uniques though. Seems like I tested this back in 09 and the vendor just ate the item, and it didn't show up on their inventory even though there was plenty of room to display it.
I can see Charsi happily sitting at her stump thing with a knife and fork, chewing on a chunk of Windforce.
