Since the Starter Edition came out for World of Warcraft, being an unlimited free trial with a cap of level 20, I occasionally drop in and play the post-cataclysm low-level quest content that was all new to me, or try different races and classes.
I typed up all my experiences and impressions of that content, but never finished the article or uploaded it here. The basic summary is that they had stripped the gameplay and the leveling experience of at least half of its previous depth. Perhaps in the future I'll explain why I feel that way.
Now, with the new expansion Mists of Pandaria, Blizzard opened up the goblin and worgen playable races to the Starter Edition, enabling me to create a new character of each of those races and experience their unique 1-10 leveling zones.
In so doing, however, despite the new (to me) content to experience, I found that they've removed even more gameplay, depth, and immersion from the game.
At one time, you got to know your choice of class through interactions with your class trainer and class-specific quests, which provided a grounding in what it means to be whatever class you chose. New abilities were given as rewards for going through certain rituals or rites of passage, and class quests would send you out to assemble unique items perfectly suited to your class, which taught you what kind of gear you should be looking for in the future, though these class quest rewards were often so good, you'd be using them for the next 10 levels before you could find anything better.
In general, class quests were integrated into the questing experience at least all the way up to level 55 (pretty much the end of the vanilla game), when every class was funneled into the Sunken Temple for their class quests, so really, you could go through the entire game and experience new content all the way through just by picking a different class. They really made classes feel distinct and interesting, with plenty of backstory.
Cataclysm removed most of the class quests. What previously was a reward for a chain of interesting quests was turned into something you just pay to learn at a trainer. If you didn't play it before, you'll never experience the flavour that used to give it meaning.
They also removed most of the class-specific items. Warlocks don't really need soul shards anymore. Hunters don't need ammunition or pet food. Rogues don't need to brew their own poisons.
Okay, so that's all just a little summary of a couple of the small things that were changed in Cataclysm (instead of the long unfinished article on that and many other things), as a lead-up to what I've just experienced in the changes brought by Mists of Pandaria.
The biggest thing is that now, in MoP, they give you all your class abilities automatically, for free, with no training. Trainers are now nothing more than providers of basic information and respecs. The last tenuous connection to that old sense of involvement in the game world is now broken. I no longer feel like I'm a part of something, at all.
Moreover, what was previously a gold sink is now gone. What am I supposed to do with all this gold, now that I don't have to pay for talents or class-related materials?
Really, the only vestige of what class quests used to be is now only to be found in the repeatable quests for cooking and fishing. There are 5 randomly-assigned daily quests in each major city for each of those professions that send you off to do things related to that profession, with the quest text providing some feeling of being a cook or a fisher in that world, and giving quest rewards related to that profession. That's fun! And it's a shame the classes have had that sort of thing taken away from them.