The good
-The quests were alot more beter then TBC or Vanilla. You would get 5-10 quests in the same areea at a time making it easyer to level up.
-The in game cinematic, the battle at wrath gate was simply jaw droping
-The Dk starting zone was awesome
-The storyline is nice up to ulduar
The bad
-No proper progresion path. A new player that joins the game isn't supposed to do heroics, then nax, then ulduar, then coloseum, and can simply do coloseum 10 man and then 25. Nax was supposed to be the school of raiding, yet people can skip school.
Also judging from the PTR and the first boss, colloseum doesn't look like a step up from ulduar.
-Very bad 5 mans and heroics. The gear they drop as well as the gear you can get from the faction rewards and the badges, is not needed to complete nax. The reason this is bad is because it doesn't let people do much outside of raids. Runing heroics with some friends in TBC used to be quite fun, now you can't do it anymore.
-Showering players with gear. Since you can pretty much pug raids, you get voa, 25 mans and 10 mans every where and bosses drop around 3-4 epics as well as a lot of badges, geting gear is quite easy.
Normaly this would look like fun and appear like a good thing, how ever, once you get all the gear you need and have all the items, it takes a very fun part out of the game. Doing ulduar every week and farming all the bosses while you have every single item, is not as fun as when you know you have upgrades. This also allows for raids to zerg down bosses and outgear them really fast.
-Blizzard forgot how to make hard bosses that are fun.
Most hard bosses in wotlk, especially hard modes. are mostly hard because they hit extremly hard, usualy hiting for more hp then the tank has.
This encourages raid stacking as most guilds would get a dk tank and alot of paladins (hand of sacrifice) and priests (guardian spirit) to make these fights easyer.
Its also bad because its just not as fun. A hard boss should be hard because it requires complicated tactics and every one to play perfectly (lady vashj, kaelthas, swp bosses) and it shouldn't be just hard because of the damage he does and the healing required.
-Removal of atunments.
While I do understand that some atunments were annoying and should of been removed (onyxia, tempest keep pre nerf, karazhan).
The last atunment blizzard made was actually quite fun (entrance to black temple). The reason it was fun was the amount of lore it gave and the fact that akuma kills you at one point and then resurects you.
And what else is more epic then fighting shoulder to shoulder with maiev shadowsong to gain entrance in black temple?!
The reason this atunment was nice is because it gave people something to do outside raids wich is something that is lacking at the moment in wotlk.
-Removal of good craftable items
Again something else you could of done outside of raids was crafting items such as belt of blasting, or bop's for your own professions. While it was a bit of a yawn, it did make a a player feel proud of himself while looking at the overpowering belt he created for himself.
-Bring the player not the class.
While I agree the ideea is nice, it should of been implemented diferently. The reason its bad at the moment is because good guilds that do hard modes, still stack classes.
Its also quite annoying due to the fact that people don't feel like they're contributing to the raid that much.
The way it should of been done how ever would of been to remove bosses that require a certain class to down them (ros's deaden, ilidan's sheer, leotheras's demon form etc) as well as make blood lust the way it is now.
Making debuff's and raid buffs raid wide isn't the best way.