It's exactly two months after TGT's release and I feel now especially after the Warsong Commander nerf it's time I do a posthumous TGT review and how I and others were right/wrong on certain cards/trends post TGT.
I think it's safe to say now that TGT didn't really slow down the game to the level that most people wanted. That is to say that most combo/control decks aren't strong enough to survive against the field of decks that are being played. Gimmick decks are punished even more than they used to.
It's safe to say that the winners of TGT were Paladin and Druids. Before TGT I predicted that Druids and Shamans would be the winner with Paladin coming in 3rd but Mysterious Challenger put Paladin over the top. IMO Shaman still got plenty of good cards but the class itself is still flawed. The new cards Shaman got actually get use in their decks as staples but the decks themselves are tier 4 status. Most other classes remained the same getting a couple of new cards to play with. Rogues and Warlocks gained essentially nothing from TGT but Rogues at least got stronger in the Arena.
I think top 5 cards TGT now that everything has more or less settled are the following (in terms of meta game impact, I would easily add in Thunderbuff Valiant here because I do believe the card is that strong but it doesn't belong in a strong enough deck yet):
1) Mysterious Challenger (I put it at #1 because this card enables a new deck type single handedly and the deck itself is tier 1 status, probably best in the game. This is the Grim Patron of this expansion)
2) Darnassus Aspirant (provides Druids with a needed 2 drop and more consistency in their ramp)
3) Living Roots (another card that you can hit face with, remove minions or flood the board. Amazing in Aggro Druid)
4) Murloc Knight (a staple in Midrange Paladin now and with Warsong nerfed Midrange Paladin is actually pretty strong now. While most Paladins got maximum greed with their aggressive Secret decks, Murloc Knight is still a very strong card. I personally undervalued this card initially because I failed to appreciate the fact that Murloc Knight is himself a Murloc and many of the cards you get from the card have synergistic effects with Murloc Knight that boost the value of the card beyond what you can calculate from raw card stats)
5) Justicar Trueheart (people are now realizing that it's also good in Paladin especially the Midrange version. It's a staple in Control Warrior now.)
Honorable mentions: Wyrmwrest Agent/Chillmaw/Twilight Guardian as they enabled a strong Midrange Priest list which is something that the class really needed. I would also put in Savage Combatant in the honorable mentions list as it's regularly used in both Druid lists.
Other cards have been seeing regular rotation like Competitive Spirit, Bash, Nexus Champion Saraad, Spell Slinger, Argent Horserider, King's Elekk, Bear Trap, Holy Champion, Effigy, Confessor Paeltress, Druid of the Saber and many of the new Shaman cards like Totem Golem, Thunderbuff Valiant, Elemental Destruction, Healing Wave, Tuskar Totemic etc. but they aren't as hugely game changing as the previous cards.
As you can see from the top 5 list... almost all of them are either concentrated in the Druid or the Paladins. And no surprise that those two classes are at the top with multiple deck types.
Now that I listed the top 5, it's time to list the top 5 most OVERRATED cards from when TGT was first announced (including myself). This is the list of cards that people thought would be amazing but now no almost no one is using it.
1) Gormok the Impaler: When people were looking at top Legendaries, Gormok generally made the most top lists. People thought it would be a shoe in for Zoolock lists. Well players did try it but the card felt underwhelming. The requirement is just too steep for the effect.
2) Varian: Almost everyone thought this was a top 5 card in TGT. And who wouldn't, the effect is insane. But the card hasn't performed as well as some people would like in the standard CW list.
3) Eydis Darkbane/Fyola Lightbane: Another set of Legendaries that people thought would be amazing but didn't end up being that strong. There aren't enough cheap buff cards in the game yet and these cards tend to just be worse Spider Tanks in most cases.
4) Pretty much any neutral Inspire, hero power based minion. Maiden of the Lake, Garrison Commander, Fencing Coach, Frost Giant etc.
5) Pretty much any card with Joust on it that isn't King's Elekk. Most people didn't think Joust would be that successful but it has been even more lackluster than initially expected.
Honorable mentions: Polymorph Boar, Mulch and Seal of Champion
I am still a big fan of these cards and I still believe that a card like Mulch is genuinely good but it just doesn't fit into the current top tier Druid decks. There are 3 things that Druids care about... if a card can do damage, if it can draw or if it can ramp. If it doesn't fit into these 3 things then the card won't get played and sadly Mulch can only remove.
Just like Powershot and Dreadscale are amazing control cards but they belong in a class that doesn't care about anything that doesn't do face damage or is ridiculous cheap.
Some of these cards might change around over time of course.
Now let's look at how the new cards have stacked up with staples from before.
Blizzard tried to introduce many interesting 4 drops to compete with Shredder. Well Shredder is still the top dog 4 drop in the game. Savage Combatant, Murloc Knight and Holy Champion are good 4 drops but Shredder is still the best and most commonly used 4 drop. After the Warsong nerf, even more decks are using Shredders because everything has become so tempo driven. So despite Blizzard's efforts, Shredder is still unphased and continues to limit design space for both 4 drops and 2 drops.
As far as Legendaries go, TGT was probably even more underwhelming than GvG. Only one Legendary sees any consistent play and that is Justicar Trueheart. If it was even possible... Blizzard somehow managed to make Dr Balanced even MORE common than it was once was. So Dr Balanced still remains the #1 Legendary in the game by quite a margin.
TGT tried to introduce some Grim Patron counters like Chillmaw but in the end TGT did absolutely nothing to reign in the strength of the deck. Eventually Blizzard was forced to nerf an old card just so the newer decks could shine. Well they succeeded in that front because their new poster boy TGT Mysterious Challenger now has the highest rank among decks.
As far as spells go... TGT failed to introduce many powerful control based spells or at the very least it introduced those spells to classes that had no use for it or it introduced worse versions of already existing spells. We got Enter the Colisseum for a class that doesn't need more board wipes because it has the godlike Equality Consecrate combo. We got Powershot and Dreadscale for a class that doesn't play control. We got Flame Lance for a card that already has efficient removals. We got King's Defender and Bash for a class that already has efficient removal. And we got a bunch of much needed cards for a class that is flawed as hell right now (Shaman). So in general the control aspect of TGT failed because it introduced a lot of redundant or less efficient cards than before. That's one of the main reasons why aggro/tempo has been so rampant, the deterrents were never really presented to begin with.
TGT actually didn't introduce many aggressive cards yet still has caused there to be an aggressive meta. Argent Horserider, Lance Carrier, Competitive Spirit, Brave Archer, Living Roots are some of the few aggressive cards they introduced but most of these aren't really used all that much. The reason for the increased aggressive meta is a combination of a Warsong nerf which opened the floodgates for aggro to get out of control and the lack of good answers to aggro from TGT in general.
Other failed experiments of TGT (well currently that is, note that many of these can and will change in the future with more cards):
*Pirate Rogue - Still gimmick status.
*Discard Warlock - Even worse than gimmick status.
*Jousting in general is a failed mechanic.
*Grinder Rogue - They introduced the Nerubian cards for Rogue it's less than gimmicks status at the moment.
*Control/Spell based Hunter - Nope, still not a class that can run a decent Control game.
*Taunt based Warrior deck - Nope.
*Inspire/spell damage based Mage deck - Nope.
*Shadow Form priest - Still not there yet.
Successful experiments of TGT:
*Secret based Paladin deck
*An aggressive Druid deck (though not the way that Blizzard probably wanted)
*Token based Paladin deck (somewhat successful in the form of Midrange Paladin)
*Beast Hunter (somewhat successful in the form of Midrange Hunter, we do see some of the newer Beast cards used like Bear Trap, King's Elekk and Ram Wrangler)
*Heal based Priest deck (successful in the form of the new Control Priest that has used Holy Champion is a major threat, see Zetalot's list that he took to rank 1 EU Legend)
*Totem Shaman - It's a tier 4 deck but there's at least something here. The new totem cards introduced are definitely strong. This deck is a few cards from being completely legitimate. It just needs a Muster for Totem or a Silverhand Regent equivalent of Totems.
Conclusion: TGT had some impact on the meta by introducing a few new deck types (Secret Paladin and Dragon Priest) but in general it didn't change the meta enough to get use out of most of the cards that were introduced. Most of the previous strong decks received limited changes except for Midrange Druid which received 3 new cards to play around with and thus increasing its power level (Living Roots, Darnassus Aspirant and Savage Combatant). Control Warrior got Bash, Variant and Justicar where as Midrange Paladin got a few new tools as well. Classic decks like Handlock, Freeze Mage, Oil Rogue received almost no new good tools. Only a few of the Inspire cards are being used and Joust, a mechanic put in to counter aggro, was a massive failure. Many of the tribal or synergistic cards they introduced weren't very successful. More importantly the spells they introduced were extremely lackluster which has resulted in a meta game that is extremely tempo/aggro oriented. It's all about playing minions on curve now and finishing games quick... card draws, heals, big Legendary drops or just in general value plays be damned. Shredder is still the best 4 drop, Dr Balanced is still the best Legendary. Druid and Paladins were the clear winner of this expansion because they got some very strong cards for their stronger deck types. Shaman also got some very obviously strong cards but the class is obviously very flawed as a whole and thus struggles to make anything work. It's hard to pick the biggest loser of TGT between Warlock and Rogue. Rogue and Warlock got absolutely nothing new for Constructed in terms of high end decks but Rogues at least got much better in Arena where as Warlocks got worse in Arena and worse in Constructed.
To talk about Arena, Paladin and Rogues got a lot stronger and Mage got weaker. Warriors actually got a lot weaker if that was even possible. Arena meta is also very tempo driven and the one who gets their board to stick generally wins due to all the Inspire minions that allow you to win more. With less good spells to comeback with, Arena is also all about tempo and Rogues are excellent at tempo and thus easily a top 3 class with Mage and Paladin, though Rogues are harder to play with. Paladin is the most popular class on Arena and probably the best overall class as well for the average player. Arena tier list is pretty much Rogue, Paladin and Mage as top 3, everyone else with Druid having a lot of consistency and then Warrior in the irrelevant, never ever pick tier.
TL;DR version of TGT: