Given standard is, (we assume?) about 1 month away, a predictions thread for existing cards would be fun. This post inspired it:

I don't agree, obviously, but wanted to document some of the community's thoughts. If possible, would like explanations too. It's fine to argue at either end of the spectrum; of course, we dont know what new cards the expansion is bringing.

I figured I'd list the common cards lost that get played very regularly first.

From Naxx...

Zombie Chow (1)
Haunted Creeper (2)
Mad Scientist (2)
Nerubian Egg (2)
Deathlord (3)
Shade of Naxx (3)
Loatheb (5)
Sludge Belcher (5)

From GvG

All Mechs
Piloted Shredder (4)
Antique Healbot (5)
Dr Boom (7)

Bolded shredder because I actually think it's the most commonly played card in the game. Everyone has it and it became the de facto 4 drop. Also, lol @ GvG, they added a ton of Paladin class cards (and to a much lesser extent, Mage, Priest, and Warlock) but Naxx was just a lot more impactful.

My submission is Sen'Jin Shieldmasta. 4 drop, 3/5 taunt, basic card. Totally boring. But here's why:
-I think with the removal of the Shredder, a lot more somewhat played but never commonly done so because of Shredder power level will become reasonable
-It's already played in defensive decks, like a 1-off in reno or specific taunt decks
-Sen'Jin has always been solid in stats and value, but is defensive in focus...
-Which I think is important, because (before knowing the nerfs to aggro cards like leper gnome and knife juggler) the common tools (Belcher, Healbot, Chow, etc.) are all being removed

I still play Sen'Jin. I like it. It's far from common, but imo, one of those fringe-y cards that with the removal of about 15% ish (~5? from each deck on average?) of pool will be seen fairly often. I hope so anyway!

depending on what the new set looks like and how they nerf the druid combo i think mulch could start getting played in fast druid decks.
there is just no spot for th ecard in the current builds but i think the card has potential.

Twilight Guardian > Sen'Jin, though. With a lot of good minions out of the game or possibly getting nerfed, dragons will become a pretty good option.

But in general board clears will get more efficient without sticky minions like creepers, shredders and minibots and there will be less tempo-oriented decks.

All these predictions will of course turn out utterly wrong due to cards from the new expansion.

One of the biggest stated reasons for retiring old sets is that so new sets would be more impactful.

They have to know what sort of holes they are creating with the cards that are going away, and as such they new set will probably have a lot of cards designed to fill those holes.

probably all board wipes get a buff without so many sticky minions, not sure about stuff that loses power given that cards like shredder, belcher dont really have a direct counter.

Prediction:

Tempo mage will remain strong. Losing flamecannon and unstable portal, but with the probable addition of new decent spells, this should not be devastating. Failing that, torch could replace flamecannon. I'm optimistic (my favorite deck archetype so i'm biased)

Flamestrike probably becomes decent in that build as well.

Also scientist which is a huge tempo swing if you can get an early secret up vs playing it from hand on turn 3. I guess you can just sub kirin tor mage but that requires more setup.

I forgot to include scientist but a lot of decks are hurt by that too. I also run duplicate/counterspell which require slightly more planning than mirror entities so i don't think the deck is broken by the lack of scientists

Flame juggler will be in every face and tempo deck as the go-to replacement for MS and Haunted Creeper.

Curse of Rafaam - Simply because locks are losing 2 mana cards and it's already fringe.
Raven Idol - If combo druid is nerfed, i'd imagine blizzard tries and start a new Druid archetype. If it's control, Raven Idol seems incredible in control druid.
Arch-Thief Rafaam - Was being used as a fringe card until the meta got too quick. If it slows down again this becomes one of the first cards back in.

Ancient Shade and Eerie Statue might finally see play if BGH gets nerfed, along with many other 7+ attack minions

Rafaam is the ****. He's accused of being a win more card but i've had some thrilling comebacks with him. I'd be excited if he's used more in the new meta, he's a really interesting card.

Aggressive decks that can consistently curve out early will continue to dominate. The meta will not slow down at all

that's kind of a silly statement. If they added a 1 cost card that dealt 3 damage to all minions with some kind of condition the aggressive meta would totally shut down. It all depends on how blizzard is gonna deal with it.

It's even sillier considering like the top 5 decks on tempostorm right now have 4 controlish/midrange decks in them. Mech mage curves nearly perfectly and can ramp like crazy but is not dominant at all as another example.

This is my prediction and I'm sticking with it

???

Firstly none of these are control

Midrange druid: Relies on combo to kill you at 16/24 hp
Secret Paladin: Curves out MC on 6
Zoolock: Tries to win by turn 4-5
Patron: Tries to combo out Patrons

Boy those sound like fun decks to play against

lol ^

agree with searix

combo druid, or midrange, is often called fast druid too. (altho obv not aggro druid) secret paladin isn't aggro in the super traditional sense but clearly kills you turn 6-7-8. zoo has always been the hipster model of a "aggro but not really aggro" deck, but make no mistake, it's def closer to the aggro scale.

patron is unique, or, was. now it's def more control but not quite like pure control warrior

5) freeze mage is a convenient one you left out

Pure control is fun to play against? At least against aggro game is over by turn 5--either they won or I've gotten so much board control they can't do ****. MR, a little bit different but if I switch board control or get out of combo range they are in big trouble as well.

I hate playing against CW although I can beat it with a ton of decks b/c the games typically go to fatigue. CP isn't much better.

There is so much variation in deck play right now that i'm disappointed that they are going to get rid of cards for the standard format.

I think what they are proposing is necessary but a little too soon. Pally/Druid are slightly stronger than everything but almost all classes are playable even Rogue if you are good at it. All classes have multiple ways to play e/c Druid (although Taunt can work). While games aren't that much fun against Secret Pally, I think adjusting the power or creating a counter card would be better than creating an entirely new format right now.

Yeah, personal preference obv but I'd rather lose to face hunter/shaman in 5 min then labor through a CW game.

I think Garrison Commander could be a strong or at least often used 2 drop in control decks. It works great for Priest and could work well for other classes. Priest has a dearth of 2 drops, though, and Museum Curator is trash without Velen's following up imo.

Having a 2/3 body is itself pretty nice for tempo and being able to actually kill things like Knife Juggler, but Garrison Commander is not a bad card to draw later in games as well -- especially when trying to hang on vs aggro decks.

yes

by far the most interesting games to watch and play in are ones like kolento using elise priest against elise warrior or reno value mage and having to do things like "make decisions" instead of playing the highest cost minion you can afford every turn

Yeah ^

I literally laughed at the post saying he preferred playing against aggro shaman. Just go play candycrush man

I feel the loss of healbot and belcher hurts control a lot more than the loss of shredder for aggro.