Personally I believe that the axis of Azeroth is quite a bit different from Earth's. Such that if you look at the maps of Kalimdor and the Eastern Kingdoms. A somewhat cooler seasonal conditions are at the northern ends of the continents, and it appears to get warmer the farther south you go. Either to the deserts of on Kalimdor or the jungles of Stranglethorn.

Perhaps the Sha are a fragmented, weaker and more containable form of elder god. Our presence in Pandaria is going to cause those fragments to coalesce.

Carune:
The temperature variation makes sense if you imagine that "the known world" so far is only, say, the top half of one hemisphere (at most) - with Northrend near the north pole and Stranglethorn and Tanaris near the equator. There might be other unknown continents far to the south.

Up until now, it's been assumed and/or presented as if Kalimdor, the EK, the Maelstrom and NR take up the whole globe, but that's clearly not true, if only for the revelation of Pandaria's existence. Time to redraw all of those maps...

(As an aside, the ancient Greeks made a pretty good estimate of the true circumference of the Earth by precisely measuring the distance between two wells, and when the Sun shone straight down them (ie, noon). They ended up rejecting the answer they got because it implied (correctly!) that everything they knew about was TINY compared to the total calculated area, and THAT couldn't be right...)

But much of the "known world" is drawn on a globe created by the titans who approached this planet from the outside.

Then again, it was drawn before the Sundering, so maybe what we see is how it was before the Sundering and there is plenty of room not discovered.

Or if it continually reflects the actual planet, given that this planet was manufactured magically could cause some inconsistencies with the weather if that magic is left. In other words, the magic that created the mists may very well have been created magically in a way that required warmer climate and therefore produced them.

And I just thought about this, but it really makes me now question why Azeroth has a moon, if not 2, and if maybe one of those turned out to be a watcher and thus disappeared at some event unbeknownst to us because it wasn't really a moon. The next question to that would be where it went and what will come back with it when it does return.