Utu and I just did some math.
It makes sense for in-ame azeroth to be at 1/200th scale to Azeroth if it existed.
EDIT: this was done assuming Kalimdor is the size of all of North America (about 4,500 mi from top to bottom) and assuming a gryphon flies at 45mph.
That’s about right, average running speed is about ~10 mph and maxed out flight (for non DKs and Paladins) is 451%.
(DKs and paladins fly at 49.2 mph, obviously)