If you are unaware, population was unexpected even on retail wow to the levels they had. To remedy this they came up with a system where the more people in the zone (or local area possibly, the specifics were never explained that I know of), the faster things would respawn in the zone (this surely had some limits, probably had a lower limit among other variables, but it vastly improved the experience). While there is no known values to find (that I know of), there were blue posts on the subject, but in any case, it would would be a great change to the mangos defaults, and would help with some of the longer bugged spawns as well.
I say this just as a suggestion, I'm about to hit 60 anyway and this wouldn't impact me much, but if the server continues to enjoy such a population as it is now, the change would be welcomed. The dynamic re-pop applied to both NPCs and game objects.
Aside from more info from blue posts, there isn't much info available but I was able to dig up this:
http://www.wowwiki.com/Spawn
" Additionally, if an area is heavily farmed, and the mobs are killed very quickly right after they spawn, the game may switch to a fast respawn mode for that area, which means that mobs and resource nodes return much more quickly, usually within one minute" granted this is not a true vanilla source, if someone could find the blue post from early vanilla to help proove this that would prolly be ideal, but even from watching Joana's videos you can tell to some extent that the repop was not a static mechanic like it is on emulator servers.