This.

does anyone notice that there's almost no snow / tundra / cold region in the southern tip of Eastern Kingdoms or Kalimdor? My guess is that both continents are ABOVE the equator. If Pandaria is below that equator, it would make sense that it's so huge, since it doesn't have to "fit" in any of the existing map.

Maybe Azeroth is tilted 90 degrees on it's axis.

presumably, Azeroth has an axial tilt like earth - think about Cape Town, South Africa (33.5 degrees S latitude) v. the Kashmir (33.5 degrees North Latitude). The south has less land (each contentment tends to taper toward the bottom - see Africa, South America, IRL, Uldum and Stranglethorn in Azeroth). Less land = more water = warmer temperatures because water tends to store heat and move heat.

Azeroth isn't in our universe, and doesn't have to follow the same laws of science (Shape-shifting dragons say Hello).

"Pandaria is pretty much Southrend (along with the warm weather that southern Azeroth tends to get)."

I misread that as "the warm water" and had a disturbing mental image of pandaren standing waist deep in water with a slightly strained look.

Going to clorox my brain out now.