I don't we'll get Nurgle since they MIGHT be relegated to Boltgun's Caedo adventures, while Slaaneesh is, let's face it, too hardcore for GW to approve in a game. When was the last time we had Slaaneshi demons in game? And what sort of units they could go with anyway?
So best bet is Khorne and Necrons + everything they import from SM2, as they should.