Expansions though, for some people, are supposed to be the thing that doesn't just expand the game, but changes the face of the entire gaming world. "More of the same" is just not good enough for them. But as much as I, too, would love to see more innovation in MMO gaming, and even World of Warcraft in particular, I have to tell you, folks, Blizzard is made of mere mortals and some of you may be setting your expectations a bit too high.
No WoW expansion can ever totally revolutionize the MMO genre, because at this point the genre is mostly WoW. While there are, of course, other games out there, WoW is the current MMO superpower, with a population larger than some countries of the world -- it defines the standard upon which to improve. To "revolutionize" the genre, you'd need a different, better game, because for WoW to change too drastically would mean turning the game into something other than what it is: replacing the current game with entirely different mechanics, ways of playing, even reasons for playing altogether. Expecting WoW to become something other than what it is unfair, even if that were to be an improvement, because then it wouldn't be WoW anymore. It could also be a financial disaster to keep the name but change the game, as the fiasco with Star Wars Galaxies proved (read up here to find out how their "revolutionary" New Game Enhancements turned out).
I could turn this post around and ask you, "okay, so if you want new revolutionary gameplay, what would it be?" but the fact is that none of us (or very few anyway) are professional game designers, and we're likely to submit our cherished opinion without realizing the flaws that may make it unworkable or very unpopular. As a blogger who has now and again posted an idea I thought was innovative, I've seen a number of people shoot it to shreds and show me that it might not work as well as I thought, or help me realize maybe that aspect of the game is just fine the way it is.
At some point, many WoW players make a turnaround in our view of the game. We admit that we may have started out playing because it's innovative or revolutionary, but now we play it because it's fun and rewarding to us -- We may need to stop for a while now and then, but we keep coming back because to us it feels "classic," not "old and done with". So "more of the same" from Blizzard is a good thing in this case. Just like when you keep reading your favorite author, or eating at your favorite restaurant, or even hanging out with your best friend: you hope they will develop and expand what is already good in them, but never ever change the core, because the core is what you really love, and everything else just adds to it.