My Harestar deputy prediction is Sedgewhisker: they often tend to choose cats we've seen a bit more, and she's not too old but not too young either; she went on the journey to the beavers and all.
My prediction for SkyClan is that Dovewing and Tigerheart will go there so that they can be together. Probably Violetpaw too, since she really has nothing left for her in ShadowClan. Twigpaw I'm not so sure of, but I'm thinking probably so - I bet partly to be with her sister, and partly because ThunderClan's let her down too many times. And yeah, Alderheart I'm guessing will go: ThunderClan's not gonna keep 3 medicine cats forever, especially not when one Clan has none.
This book felt surprisingly like the end of an arc, I can't believe we have 3 more books to fill yet! I'm guessing at least part of it will cover SkyClan finding a territory and settling in. I wouldn't be surprised if they end up dragging the Tribe into things too somehow.