Many people have been saying it. I didn't understand at first, but now I really, really do.
Cata is a kids' game.
Well... not all of it. I should really say, parts of Cata are like a kids' game. I stepped into Vash'jir for the first time today with my Level 82 priest (bf and I are levelling in Hyjal so I couldn't go there without him) and found myself in Finding Nemo. Although, I have yet to find Nemo (I have no doubt I will).
I was told to head off on an underwater adventure, where I could magically breathe like a fish and sprint speedily around on the ocean floor. I had to search for treasure, collect gear for the big bad Alliance troops and save my friends from drowning. And I got given a cooooool seahorse to ride around on.
...oh, wait, you thought I was being sarcastic?
Nope! I love it. It's so easy and fun, and I'm constantly giggling with glee at the fun quests I have to do. The XP just keeps coming. I'm progressing fast and getting heaps of greens to gear up with and DE, and did I mention having fun? What more could I want for the first few levels of a new expansion, after being so bored and frustrated with the game for so long?
Challenge, I hear you say! Yes, I want a challenge. But having already levelled my mage to 85, I know that's coming in Twilight Highlands. And after I've been primed not to expect things to come so easily as they did going from 80-83, I'll have heroics and raids to go on to.
Kudos, Blizzard, nice job!