The thing is too, there's a lot of variables being introduced this time. Naxx was really just, here's some deathrattles! GvG, here's a bunch of mechs! BRM, look at these dragon synergies!
With this one though you have: jousting, inspire, hero power interactions, more dragon synergies and every class is getting new archetype possiblities introduced. Beasts for hunters and druids. Push towards more minion/tempo options for rogues. The whole discard synergy shit for locks. Priest and shaman getting a host of options. So instead of just one gimmick, they are dropping numerous ones at once. That's something to be hopeful for in terms of the game getting shaken up a bit more than usual as people mash shit together and see what happens.
I just dislike the joust nonsense because everyone in the game from casual FTP to pro streamers is sick of random and has been saying so.