Their biggest internal team is working on the next historical Total War game, so don't worry too much. But also don't hold your breath, I think it'll be a while.
The Warhammer thing is this three game, ten year plan, which seems kind of crazy. But I do like what they've done so far. I just got the base game, but the free DLC and patches have kept it fresh for me. I can't begrudge them making money off this.
Is Skaven confirmed? They said there's four races in Warhammer II and the trailer only shows three plus a rat. Please be Skaven. Unless they've not found a good way to do Skaven, in which case hold off on the Skaven please!
To be honest, I'm not sure I see my vision of Skaven working inside the Total War formula. They should be burrowing under the Old World and hatching schemes, not engaging in pitched battles.