Every faction and character I care about is in WH1+2. WH3 holds very little for me to get excited about and that almost all down to Chaos Dwarfs, but I can live without them just fine as well. Ogre Kingdoms I never found anything endeating about, for me they're just pink, overgrown Greenskins with half the appeal. Their theme being gluttony...whatever. Daemons of Chaos I never liked, they just should have never been made into a separate armybook in the first place because I find the faction just doesn't work this way. Kislev, if they're faction #4, what exactly is their selling point? Ice Magic and bear cav or whatever don't look like much considering what the WH1+2 factions have already thrown at the player. DoW...Empire but with pikes and less gunpowder and maybe with some units scavanged from other rosters, bleh. Even worse if they're realised as hordes. CIN, don't even get me started of how little appeal those have with their facelessness and absolute irrelevance.
Also the setting, the Darklands and Chaos Wastes will be, well, wasteland, so lots of brown and grey, flat featureless plains. After the lush greens of Lustria, the Southlands and Ulthuan or the snowy landscapes of Naggaroth (tree visibility issues notwithstanding), that's a serious step down.
From a faction and setting POV WH3 is a hard-sell. Even if CA greatly improves upon mechanics and stuff, it still means I'll wait until the combined Grand Campaign is in implemented because I have such a hard time caring for the leftovers this will launch with.