I feel your pain.
I know my problems are not with any content prior to WoLK. I just had a blast running some DK's through Nagrand. I did EVERY quest there.
There is only one collection quest with less than a 100% drop rate and only 1 quest where you throw a rock at something requiring you to look in your bag.
I have a feeling that I won't want to continue playing them when I get them to 70 because WoLK questing just sux.

I know exactly what you mean about the uni-class. many of the quests in WoLK are uni-class quests. any quest where you mount something is completely unrelated to what your character is.
in theory, a character with less hit points should do more damange and a character with more hit points should do less damange.
I remember hating to level a pally (solo) because it was torture to kill something, now a pally is not any differernt to level than anything else in the game.
we just did Naxx10 with the oddest group and did just fine.

I hate nerfs and they are constantly modifiing stuff and they aren't just small changes either.
I've been noticing that they nerfed the crap out of shaman to force us to play other characters only to retore shaman to the grandure a few months later.


Maybe I'm just burnt out too.