I voted for the second - "monsters everywhere" - because I'm thinking more on the Minecraft + Dragon's Dogma line of thinking. Maybe not exactly everywhere, just in a way that makes them realistically plausible. If there was a shadow they wouldn't really pop out from there, only in places somewhat away from the player. Real creatures should roam around everywhere, day and night. Monsters should be able to pop up (naturally) from their given surroundings during the night, but not from any random shadow. We won't have zombies or mutants so that's a breath of fresh air.
Dragon's Dogma had night creatures done interestingly, though stupidly kept them in predictable places. Phantoms would roam dense forests, ghosts for graveyards (idea from this forum), and anything else that I can't think of being in their other areas. They shouldn't pop out from the shadow, or darkness, like mobs in Minecraft do. I wonder if it sounds contradictory because certain conditions have to be met from what I'm suggesting because that doesn't really give them many places to spawn, which also might be what some people are seeking.
I'll still love to see the natural animal predators roaming about. I'd also love to see monsters 'everywhere' in that they come out of random, yet semi-specific places. Some even to their biome.
(editing out retarded typos.)