I got a strong feeling this will happen. The battle will get really epic and it will draw out a new power for Kakashi, which will be Amaterasu. If you think about it, it makes perfect sense.
1.Look at this:
In my opinion, in chapter 605, the "hell" that Obito was talking about was the genjutsu known as Tsukuyomi. In other words he unlocked it at this point in his childhood. And if all this recent talk about the sharingan eyes supposedly growing as a pair/at the same time is true, then Kakashi may either have already have Amaterasu lying dormant in his eye or he's pretty close to unlocking it.
2. Kishi did say he was planning to give Kakashi a serious upgrade. Giving him Amaterasu would not only be a serious upgrade but it would also fall in line with the plot of the story and the way things are supposed to work with the sharingan in Naruto.
Personally I think Kakashi getting Amaterasu would be epic. I know Obito managed to escape Itachi's Amaterasu but with Kakashi's percision ability from using Kamui so much, maybe he can use his Amaterasu to hit Obito's eye before he can teleport or something. I don't know just throwing something out there