First, Now that Tavi has found his Furycrafting there's no reason for him not being proclaimed as heir, other then him becoming a target.
Second, Recall that the First lord Gaius warned Tavi to be careful in his intimacy with the Margat "Kitai".
Third, Tavi will NEVER accept any future without Kitai as his mate. She is bonded to him, even to the extent that she has developed Furycrafting.
Fourth, Isana and Fade have faced their past, and seem to have accepted their role are pair bonded/married.
Fifth, Isana will not stay in the camp of Aquitine, and Fade will support/defend her.
Sixth, Tavi allowed the female Canim to flee, he also has good links with Varg, as well as the leader of the Warrior caste, and this hints to some very interesting potentials.
Seventh, All, or all that were known of the canim seers/priests were slain, this may very well allow a dipomatic solution with Tavi acting as the Aleran emisary.
There are more points, but those are the ones off the top of my head.
I wish Jim had some good maps of his world. Maps are a good thing, as is a glossary, espcially with a list of who's who.