Zeschuk said: "It [World of Warcraft] is a touchstone. It has established standards, it's established how you play an MMO. Every MMO that comes out, I play and look at it. And if they break any of the WoW rules, in my book that's pretty dumb."
What's interesting is how Zeschuk, sitting with Mike Morhaime at the keynote panel, gave WoW the reverence it deserves as the leading industry standard in MMO gaming. Instead of couching his remarks about the specific game he was in the process of making, he discussed how players expect a set of established standards that WoW has provided. Be it a sense of completion of polish, a game mechanic, core concepts, or even art direction and fluidity of art theme, World of Warcraft set the bar very high for other game developers and even Blizzard itself.
We know WoW is big, but I think we sometimes forget how important it is as well. Greg Zeschuk and the rest of the video game industry know this and acknowledge that breaking some clear-cut rules is a big mistake.