I think it's mixed with a few cleared up rules and some major **** ups. A standard, non-cheesed out drop pod list with 6 troop choices can dump *18* scoring units that can't be contested except by other battle forged troop choices (12 Combat Squads and 6 pods). WTF were they thinking???
Also, those armies with very few psykers will never get off a single power against even mild GK or Tzeentch daemons. I pointed out my normal, fairly tame 2000pt GK list and I ended up with 18+d6 dice to cast/dispel with. If I can't get enough 6's to stop pretty much everything from my opponent then something is wrong. This new mechanism is just flat out broken at the higher levels.
Finally, while I like the concept of summoning daemons, I have a fairly benign Tzeentch army (no screamerstar, etc.) and at 2000 pts I can summon about 1000-1500 extra points worth of additional daemons within the first half of a game assuming a relatively decent spread of powers from the new Malefic discipline. Who in their right mind wants to play against that?
So while I think some of the clarifications were fine, the new rules they introduced were clearly not playtested at all. Even a modicum of actual testing would have revealed the above can happen even with relatively fluffy armies. Plus, they still didn't do a d*mn thing about the idiocy that is the 2++ rerollable issue. Honestly, I don't think they even care about the game anymore. Except for the few clarifications I'd rather play 6th.