I wrote in the german thread:
Open World Respawn: None. What is dead is dead.
Dungeons: No fast respawn while you are in. It destroys the believability of the world to go into a dungeon, kill everything and when you are on your way out (nothing else, just going back where you came)... it's full again. I mean... HUH? Respawn when you re-enter is fine. If you want to have a respawn, you can spawn only a few monsters for the way out.
Places like "Kr�hennest" (the from undead infested part of the city in the Addon): It is very annoying to kill everything outside, enter a house, and when you leave again being surrounded by a full load of all fresh mobs.
Here, you can have a full spawn for first time entering (no one has killed them yet) and then spawn like 1/5th to 1/3rd of the enemies each time you leave a house (maybe with a cap of 1/2 of the first load).
All in all, no matter what, you have too many and too fast respawns right now.
