I am 15000% positive it is not my connection. This is something that has been happening on my paladin since Wrath. I usually have less than 50ms latency to the WoW server and 15ms to my Vent server two states away. I usually only experience it on my paladin that has 492% flight speed. My other characters that are slower (450%) aren't quite as bad.
I've recently just built a new machine which I guarantee is better than 95% of the WoW playerbase has and it still happens regularly. It is just how WoW deals with loading things in when moving at a high speed through the zone.
I have no issues in other games. Like I said, this is an oddity that I have been dealing with on my paladin since they put in 310% mounts. There have also been times that I've landed in Sunsong Ranch and had to wait 10 to 15 seconds before the players "appeared" in around me.
I really think WoW servers just sometimes cannot handle the amount of load created when players are zooming about at nearly 500% travel speed and there are several players in the area. For all I know, that might be one reason they want to wean away from flying mounts - maybe they have some tech issues they are having trouble resolving. It would also be reasonable to assume other MMORPGs avoid flying (or ultra fast movement speeds) for that same reason.