I certainly hope that Dr. Fate's appearance will go beyond this one panel as I am very interested to see how he fits into this war which is lead mostly by magic and mysticism. I also wonder how much Nabu knows about what is going on. If you all recall, during the Flashpoint event, Kent Nelson knew that there was something wrong about the world they lived in:
In the above panel, as he is dying, Kent tells Deadman that he wasn't supposed to be there anyway. Another thing that intrigues me is, if the Helm's power will have any effect on Pandora's Box? In the Flashpoint event, the Amazons were very interested in getting their hands on the Helm of Nabu as they thought that its power would tip the scales in their war against Atlantis.
Lastly, and I know this is a long shot here, we all know that Nightwing is going to play a major role in the Forever Evil event. Some were even worried that he was going to be killed off. I wonder if Dr. Fate will make an appearance there as well to help him, as they are connected through the Flashpoint event. In the Flashpoint world, Nightwing (Dick Grayson) becomes the last heir to the Helm of Nabu and the final Dr. Fate of that world. So who knows, Dr. Fate might show up to lend him a hand.