Such was my feeling working my way through Pandaria.
I'm already on my third zone, Krasarang Wilds, having completed the first two.* While I know two things --cross realm zones are turned off for Pandaria and I've already passed one of the big "dailies" hubs at the Tillers area-- I'm still surprised at how few toons are out and about in Pandaria itself. I've seen more toons in Hellfire Peninsula than in the first three Pandaria zones, and that's kind of scary.
There's obviously players out there, as Cynwise demonstrated in his class distribution post, but wherever they are, it's not in Panda-land.
I am not going to jump to conclusions here, but I suspect that people like me who took their time to level a new toon are outliers, and most of the utility in the new zones is already spent. As the "game starts at max level" people will tell you, that's not a surprise. But think of all the effort it took to generate the data in those new zones, and you'll understand why I'm more than a bit concerned about the future of WoW.
Just like in Cataclysm, Blizzard expended a lot of effort to create new content (and a new continent), but the usefulness of that content evaporated once the big wave made it to L90. I suppose you could make the argument that 2 years of development was useful for the majority of players up until patch 5.1 dropped, only a few months worth of playtime. That's not exactly fair, but the dearth of characters out in Pandaria feed the perception that Blizzard would be better off spending time devising new raids and BGs. (And pets.)
For those people (like me) who have complained about Blizzard's use of the WoW novels and short stories to advance the lore rather than develop it in-game, this is a pretty damning result. If you were a bean counter at Blizzard, which would give you more bang for the buck: a novel or in-game content? And what's more, if you knew the in-game content would be tossed aside at the earliest opportunity, where would you put your development dollars at?
It's a shame, really, because when Blizz' development staff take themselves and their topic seriously they can create some really good content.
*Given my current leveling rate, supplemented by BGs, I'll be at max level by the time I'm finished with Kun-Lai Summit. That's great for entering the Dread Wastes, but for a BG-er, that's going to be painful.