Keep in mind that these quests are optional, and are not necessary to continue leveling and capturing companions. They are also account-wide, so if you complete the quest chain on one character, you will not be able to complete it again on another. However, any progress that you've made will be saved and you can pick up where you left off in the quest chain on another character. The dailies that you've unlocked will also be accessible by all your toons.
Arcane: Arcane Empowerment - Clearcasting can now stack 2 additional times, and increases the damage of Arcane Missiles by 5% per stack. Clearcasting no longer reduces the mana cost of Arcane Explosion. Fire: Flamecannon - After standing still in combat for 2 sec, your maximum health increases by 3%, damage done increases by 3%, and range of your Fire spells increase by 3 yards. This effect stacks up to 5 times and lasts for 5 sec. Frost: Concentrated Coolness - Frozen Orb's damage is increased by 10% and is now castable at a location with a 40 yard range but no longer moves. Monk
WoW Classic seeks to recreate the "vanilla WoW" experience—that is, WoW as it existed before a series of seven game-altering major expansion packs from 2007's The Burning Crusade to 2018's Battle for Azeroth. To achieve this, Blizzard has rebuilt the game based on archived data from back in 2005 and 2006 (patch 1.12 is the goalpost—the current game is on patch 8.1.5). The company has committed to meticulously presenting the experience exactly as it was back then—warts and all—with only a small number of unavoidable or critical changes.
The Horde levels 50-60 guide has been rewritten and revamped. My 1-60 Horde leveling guide is now completely updated for the 1.12 Drums of War patch. As you can see it is about 15% larger than the 40-50 guide (single largest guide page yet). There is also a lot of route changes. I moved the entire Silithus section from level 55 to level 58, which allowed me to include a lot more quests for that zone. There is also a lot of other improvement to the route, including adding a lot more quests into the guide, mostly from Moonglade, Silithus and Eastern Plaguelands. This will make the final level 59 grind much shorter.
Within the context of Classic, the method most frequently proposed is to re-tune bosses to make them harder. Rather than copying the numbers, re-create the relative difficulty. Kind of like, when you first start working out, you use small weights. When you get stronger, you lift bigger weights. The WoW community is more knowledgeable, more experienced, has better hardware, etc. We're "stronger." So give us tougher bosses. There are a lot of forms that could take. Bosses were constantly re-tuned during vanilla anyway, so if Ragnaros does 10% more damage or something, is that really a problem? I don't think it is. What about resistance gear? back in the day, collecting resist gear was a thing people did. But the numbers and strategies are so well known today that only the tank really needs it anymore. Bosses could be re-tuned with more resistible elemental damage so that's important for entire raids to gear appropriately. That would be entirely keeping with the spirit of vanilla even if the actually numbers sitting in a database somewhere were different than they were ~13 years ago. If you want to go a little farther, a few people have proposed adding new abilities to old bosses, adjusting their timing, etc.
Recently the new essence received from PvP which gives you access to an extra PvP talent, that also works in PvE situations, has made waves and there are plenty of threads about it on the forums. One in particular got a blue response which clarified just how powerful and how relevant the essence is supposed to be for PvE-focused players. Each spec gets a specific PvP talent added and some of them currently selected on the PTR are a little too powerful and feel mandatory for PvE, such as Moonkin Aura for Boomkins and Leader of the Pack for Feral Druids, but Blizzard clarified it is not their intention to have must-have talents for PvE available through the essence, as its primary goal is to add additional choice for PvP players.