Well, the Juno-rewrite is being done now (slowly). Unless you mean the original novel that will kind of feel like Trial of Juno, but without Pokemon.
The general premise behind that novel would be the story of a fallen angel who gets sick of being evil. However, redemption for him is not so easily achieved because of his background, and to do it, he needs to take on the challenge of restoring peace to a war-torn world he's totally unfamiliar with. It would kind of be the mirror rendition of Kivistal, a world with only Pokemon, but in this case, the denizens of the world would be anthropomorphic animals. The good guys would be the forest-dwelling mammals while the enemies would be evil, cyborg reptiles. The protagonist becomes one of the mammal races, but he starts off being untrustworthy and has to struggle to be accepted. As the story progresses, the more the protagonist uses his dark powers for good purposes, the less evil they become. Of course, much later on, he becomes a very valuable asset to the Heaven-like realm for animals, being extremely familiar with the nature of darkness and their dark sources of power.
In all, I've never seen a story do this kind of thing, so yeah, I think it's a good premise.