Just what I think will dominate ladder in the expansion. Like the last few metas, I think it will actually be quite diverse even as it's frustrating in its repetitiveness, so I'm predicting lots of "good" decks. Not smart enough to predict their relative order of goodness though.
So in alphabetical order only, I think we'll see:
- some kind of Kurtrus DH. He's too strong to not see play, even though DH might be the weakest class right now. I doubt this will be the full blown token build, though. More likely just deathrattle DH with a few new cards.
- some aggro Druid, probably not too different from currently.
- face Hunter is the eternal ok deck, and it particularly feels strong with the new running of Arcane Anomaly.
- Mozaki mage, with Siphon.
- some kind of buff Paladin, not sure with librams or not and other details, but something. New cards including Cariel will strengthen an already strong archetype.
- elemental Shaman, pretty much the same as now except with Sleetbringer instead of Menacing Nimbus.
- some version of questlock will still be oppressive.
- deathrattle zoolock, a tempo version (rather than the Owl otk meme version).
- good old pirate questline warrior :P until it gets nerfed.
"Big Decks" like Big Demon DH, Big Beast Hunter, Big Paladin, Celestial Druid, Big Spell Mage, Deathrattle Control Priest, Control Warrior, Freeze Shaman might be fun with new cards strengthening them, but still won't be really prominent, especially in the OTK heavy meta.
I agree with most of what OP mentions since I believe that most of the new synergies will be rather mediocre relative to what we have. I think we'll see some pseudo control warrior as well. It will be rather tempo based but not a full on BIG warrior. We'll get a freeze shaman that also runs control-ish but with lots of big swing minions. Both will probably be good tier 2 decks. I also think we'll see more questline mage. It performed well at oppressing control/BIG before and it will receive some useful cards, so I believe in a good handful, but I think people will be tired of the old shit in the first few weeks (making room for lots of frost shaman + random priest decks) then people will go back to some optimized quest decks.
Demon seed domination predicted. Also quest mage. We will sure see quest warrior.
Quest Mage is not even a Tier 3 deck right now. Is Tier 4 a thing? If so that is what QM is now. I get that it gets a new 2 damage for "2 mana" that can go face if needed but I don't think that's a big enough upgrade over, idk Aplexis Blast maybe, too bring QM to Tier 3 much less dominance.
Quest rogue is still strong and will be meta if the Buff/Libram Pally remains top dog (which he is now).
Quest Warlock remains top 3 for sure. I am not meeting any Pirate Warriors after expansion, maybe people got fed up with the deck as everybody and their mom played it before Alterac 24/7.
Aggro druid also prevails, got trogg if nothing:) And freeze shaman/mozaki mage/face hunter for tier 2 probably.. so we share the same opinion mostly, except I dont see any zoolock playable whatsoever :D