I think the game's story will be about the final battle against a " ultimate demon god". Whoever kills the god will have to fill his sit and decide what to do with the realm. You can beat the campaign with all the previous races and new ones, when you finish it you get the result of the decisions of each race as a full motion video. Humans reign and fight each other, Orcs ensalve everyone else, and so.
The basic 4 new races:
1) Chaos Demons (Awaken by ultimate demon god)
2) Chaos Dwarves (Awaken by ultimate demon god)
3) Kislev/Araby (Decide to fight the great evil)
4) Cathay (Decide to fight the great evil)
That's my basic TW:Warhammer3 vanilla release. What's yours?
ps: Oh yeah and add the cinematics from WH1 and WH2 to the 3rd game not like with WH2 missing the opening scenes of the ME races.