^Is it possible to fuse ebony with a daedra soul to create daedric material?
I think that would have to be the case. The only way I could see Daedric metal being harvested without it being ridiculous is if it was located at a Daedric temple of some sort, and even then that's rather improbable.
Edit: The likely answer is you forge, say, an ebony hammer, and if you kill a daedra, their soul goes right to any ebony metal nearby instead of back to Oblivion. But then you have to forge the spirit into the metal for it to transform.
Or perhaps you wont be able to forge Daedric weapons/armor at all, and their like is very rare.